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Ko te whanaketanga o ngā hangarau hauwai kei te ngākau o te ōhanga matomato. Hei whakaritenga mō te whakatutukitanga o te rokiroki hauwai, me whakamahi ngā whakakorikori hohe me te pumau mō te tauhohenga hauwai (de)hauwai. Tae noa ki tēnei wā, kua whakamahia ngā konganuku utu nui hei whakakorikori i tēnei wāhi. I konei, ka whakaarohia e mātou he whakakorikori hou e ahu mai ana i te cobalt iti te utu (Co-SAs/NPs@NC) e honoa tahitia ana ngā pae konganuku kotahi kua tohatohahia me ngā matūriki nano pai hei whakatutuki i te dehydrogenation waikawa formic whai hua. Mā te whakamahi i te rauemi pai rawa atu o ngā waeine CoN2C2 kua horapa ā-atomika me ngā matūriki nano kua kapihia he rahi 7-8 nm, me te whakamahi i te propylene carbonate hei whakarewa, i whiwhihia he whakaputanga hau pai rawa atu o te 1403.8 ml g-1 h-1, ā, kāore he ngaronga i muri i te 5 huringa. E whakaatu ana ngā whakamātautau whakamātautau in situ, ki te whakatauritea ki ngā whakakorikori ngota konganuku kotahi me ngā matūriki nano e pā ana, ka whakarei ake a Co-SAs/NPs@NC i te mimiti me te whakahohenga o te takawaenga monodentate matua HCOO*, ā, ka whakatairanga i te wehenga hononga CH. E whakaatu ana ngā tātaitanga ariā ko te whakaurunga o ngā matūriki nano cobalt ka whakatairanga i te huringa o te pokapū roopu-d o te ngota Co kotahi ki tētahi pae hohe, ā, ka whakarei ake i te hononga i waenga i te carbonyl O o te takawaenga HCOO* me te pokapū Co, ā, ka whakaiti i te arai pūngao.
E kiia ana te hauwai he kaikawe pūngao nui mō te whakawhiti pūngao o te ao i tēnei wā, ā, ka taea te noho hei kaupapa matua mō te whakatutuki i te kore waro1. Nā ōna āhuatanga ā-tinana pērā i te mura me te iti o te mātotoru, ko te rokiroki me te kawe hauwai haumaru me te whai hua he take matua ki te whakatutuki i te ōhanga hauwai2,3,4. Kua whakaarohia ngā kaikawe hauwai waro wai (LOHC), e penapena ana, e tuku ana hoki i te hauwai mā roto i ngā tauhohenga matū, hei otinga. Ki te whakatauritea ki te hauwai ngota, he ngāwari, he watea hoki te whakahaere i aua matū (methanol, toluene, dibenzyltoluene, me ētahi atu)5,6,7. I roto i ngā LOHC tuku iho, he iti noa te paitini o te waikawa formic (FA) (LD50: 1.8 g/kg) me te kaha H2 o te 53 g/L, 4.4 wt% rānei. He mea nui, ko te FA anake te LOHC ka taea te penapena me te tuku hauwai i raro i ngā āhuatanga ngawari i te aroaro o ngā whakakorikori e tika ana, nā reira kāore e hiahiatia he whakauru pūngao nui o waho1,8,9. Ina hoki, he maha ngā whakakorikori konganuku rangatira kua whakawhanakehia mō te tango i te hauwai o te waikawa formic, hei tauira, ko ngā whakakorikori e ahu mai ana i te palladium he 50-200 ngā wā kaha ake i ngā whakakorikori konganuku iti te utu10,11,12. Heoi, ki te whakaarohia te utu o ngā konganuku hohe, hei tauira, he nui ake te utu o te palladium i te 1000 ngā wā.
Ko te Kobalt, Kei te kukume tonu te rapu i ngā whakakorikori konganuku turanga kanorau tino hohe, pumau hoki i te hiahia o te tini o ngā kairangahau i roto i te ao mātauranga me te ahumahi13,14,15.
Ahakoa kua whakawhanakehia ngā whakakorikori iti te utu e ahu mai ana i te Mo me te Co, me ngā nanocatalysts i hangaia mai i ngā koranu whakarewa rangatira/turanga,14,16 mō te tangohanga FA, kāore e taea te karo i tō rātou whakakorenga āta i te wā o te tauhohenga nā te nohoia o ngā pae hohe o ngā konganuku, te CO2, me te H2O e ngā protons, ngā anion formate rānei (HCOO-), te poke FA, te kohikohi matūriki me te paihana CO pea17,18. Nō nā tata nei mātou me ētahi atu i whakaatu ko ngā whakakorikori ngota kotahi (SAC) me ngā pae CoIINx tino marara hei pae hohe ka whakapai ake i te tauhohenga me te ātete waikawa o te tangohanga waikawa formic ki te whakataurite ki ngā nanoparticles17,19,20,21,22,23,24. I roto i ēnei rauemi Co-NC, ko ngā ngota N te pae matua hei whakatairanga i te tangohanga FA me te whakarei ake i te pumau hanganga mā te mahi tahi me te ngota Co pokapū, ko ngā ngota Co e whakarato ana i ngā pae adsorption H me te whakatairanga i te wehenga CH22,25,26. Engari, ko te mahi me te pumau o ēnei whakakorikori he tawhiti tonu i ngā whakakorikori konganuku ōrite me ngā whakakorikori konganuku rerekē o ēnei rā (Pikitia 1) 13.
Ka taea te whakaputa i te kaha nui mai i ngā pūtake whakahou pēnei i te rā, te hau rānei mā te hikohiko o te wai. Ka taea te penapena i te hauwai e puta ana mā te whakamahi i te LOHC, he wai ka taea te whakahoki i tōna hauwai me te tango hauwai. I te taahiraa tango hauwai, ko te hauwai anake te hua, ā, ka whakahokia te wai kawe ki tōna āhua taketake ka whakahauwaitia anō. Ka taea te whakamahi i te hauwai i roto i ngā teihana penehīni, ngā pākahiko, ngā whare ahumahi, me ētahi atu.
Nō nā tata nei, i puta te pūrongo ka taea te whakanui ake i te mahi ā-roto o ngā SAC motuhake i te aroaro o ngā ngota whakarewa rerekē, ngā pae whakarewa tāpiri rānei e whakaratohia ana e ngā matūriki nano (NP) me ngā nanoclusters (NC)27,28. Ka huaki ake tēnei i ngā huarahi mō te mimiti me te whakahohenga o te papa, tae atu ki te whakarerekētanga o te āhua me te hanganga hiko o ngā pae monoatomic. Mā tēnei, ka taea te arotau i te mimiti/whakahohenga o te papa, ka pai ake te whai huatanga o te whakaterenga whānui29,30. Ka homai e tēnei ki a tātou te whakaaro mō te hanga rauemi whakaterenga tika me ngā pae hohe ranu. Ahakoa kua whakaatuhia e ngā SAC kua whakapaitia te kaha nui i roto i te whānuitanga o ngā tono whakaterenga31,32,33,34,35,36, ki te pai o tā mātou mōhio, kāore i te mārama tā rātou mahi i roto i te rokiroki hauwai. I tēnei whakaaro, ka pūrongo mātou i tētahi rautaki maha-whakamahinga me te pakari mō te hanga o ngā whakaterenga ranu e ahu mai ana i te cobalt (Co-SAs/NPs@NCs) e tito ana i ngā matūriki nano kua tautuhia me ngā pokapū whakarewa takitahi. Ko ngā Co-SA/NPs@NC kua arotauhia he tino pai te mahi tango hauwai waikawa formic, he pai ake i ngā whakakorikori nanostructured kore-rangatira (pērā i te CoNx, ngā ngota cobalt takitahi, cobalt@NC me te γ-Mo2N) tae atu ki ngā whakakorikori konganuku rangatira. Ko te whakaahuatanga in-situ me ngā tataunga DFT o ngā whakakorikori hohe e whakaatu ana ko ngā pae konganuku takitahi he pae hohe, ā, ko ngā matūriki nano o tēnei mea hou ka whakarei ake i te pokapū d-band o ngā ngota Co, ka whakatairanga i te mimiti me te whakahohenga o te HCOO*, ā, ka whakaiti i te arai pūngao o te tauhohenga.
Ko ngā anga Zeolite imidazolate (ZIF) he matū-toru-ahu kua tautuhia pai e whakarato ana i ngā whakakorikori mō ngā rauemi waro kua tāpirihia ki te hauota (ngā whakakorikori konganuku-NC) hei tautoko i ngā momo konganuku rerekē37,38. Nō reira, ka honoa a Co(NO3)2 me Zn(NO3)2 ki te 2-methylimidazole i roto i te methanol hei hanga i ngā matatini konganuku e rite ana i roto i te otinga. I muri i te centrifugation me te whakamaroke, ka pyrolyzed a CoZn-ZIF i ngā pāmahana rerekē (750–950 °C) i roto i te hau o te 6% H2 me te 94% Ar. E ai ki te pikitia i raro nei, he rerekē ngā āhuatanga pae hohe o ngā rauemi hua, ā, ko ngā ingoa ko Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850 me Co-SAs/NPs@NC-750 (Pikitia 2a). ). Ko ngā kitenga whakamātautau motuhake o ētahi o ngā mahi matua i roto i te tukanga hangahanga kua taipitopitohia i roto i ngā Pikitia 1 me te 2. C1-C3. I whakahaerehia te whakapūtanga hihi-X pāmahana rerekē (VTXRD) hei aroturuki i te whanaketanga o te whakapūtanga. Kia tae te pāmahana pyrolysis ki te 650 °C, ka tino rerekē te tauira XRD nā te hinganga o te hanganga tioata raupapa o ZIF (Pikitia S4) 39. I te piki haere tonu o te pāmahana, ka puta ngā tihi whānui e rua i roto i ngā tauira XRD o Co-SAs/NPs@NC-850 me Co-SAs/NPs@NC-750 i te 20–30° me te 40–50°, e tohu ana i te tihi o te waro kore-āhua (Pikitia C5). 40. He mea tika kia mōhiotia e toru noa iho ngā tihi āhuatanga i kitea i te 44.2°, 51.5° me te 75.8°, nō te cobalt whakarewa (JCPDS #15-0806), me te 26.2°, nō te waro graphitic (JCPDS # 41-1487). E whakaatu ana te whānuitanga hihi-X o ngā Co-SA/NPs@NC-950 i te aroaro o ngā matūriki konutai kua whakakīia ki te rite ki te karāhe i runga i te whakakorikori41,42,43,44. E whakaatu ana te whānuitanga Raman he kaha ake, he whaiti ake hoki ngā tihi D me G o ngā Co-SA/NPs@NC-950 i ngā tauira kē atu, e tohu ana i te nui ake o te whakakārāhe (Pikitia S6). Hei tāpiri, he nui ake te horahanga mata me te rōrahi pore o Brunner-Emmett-Taylor (BET) o ngā Co-SA/NPs@NC-950 (1261 m2 g-1 me te 0.37 cm3 g-1) i ētahi atu tauira, ā, ko te nuinga o ngā ZIF he rauemi NC (Pikitia S7 me te Ripanga S1). E whakaatu ana te mātaitanga mimiti ngota (AAS) ko te nui o te cobalt o ngā Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850 me Co-SAs/NPs@ he 2.69 wt.%, 2.74 wt.% me te 2.73 wt.%. NC-750 ia (Ripanga S2). Ka piki haere te nui o te Zn o ngā Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850 me Co-SAs/NPs@NC-750, e pā ana ki te pikinga o te whakahekenga me te whakakorikori o ngā waeine Zn. Te pikinga o te pāmahana pyrolysis (Zn, te pūwāhi kohua = 907 °C) 45.46. E whakaatu ana te tātari huānga (EA) ka heke te ōrau o te N me te pikinga o te pāmahana pyrolysis, ā, ko te nui o te ihirangi O pea nā te mimiti o te ngota O2 mai i te pānga ki te hau. (Ripanga S3). I tētahi taumata o te cobalt, ka noho tahi ngā matūriki nano me ngā coatoms takitahi, ā, ka hua ake he pikinga nui o te mahi whakakorikori, e ai ki te kōrero i raro nei.
Te hoahoa kauwhata o te hanganga o Co-SA/NPs@NC-T, ko T te pāmahana pyrolysis (°C). b Te ahua TEM. c Te ahua o Co-SAs/NPs@NC-950 AC-HAADF-STEM. Kua tohua ngā ngota Co takitahi ki ngā porowhita whero. d Te whānuitanga EDS o Co-SA/NPs@NC-950.
He mea nui, i whakaatuhia e te karu hiko tuku (TEM) te aroaro o ngā momo matūriki cobalt (NP) me te rahi toharite o te 7.5 ± 1.7 nm anake i roto i ngā Co-SA/NPs@NC-950 (Pikitia 2 b me S8). Kua whakakīia ēnei matūriki ki te waro rite ki te karāhe kua tāpirihia ki te hauota. Ko te mokowā taha whatunga o te 0.361 me te 0.201 nm e rite ana ki ngā matūriki waro karāhe (002) me te Co whakarewa (111). I tua atu, i whakaatuhia e te karu hiko tuku matawai pōuri-ā-papa teitei kua whakatikatikahia te aberration (AC-HAADF-STEM) ko ngā Co NP i roto i ngā Co-SA/NPs@NC-950 i karapotia e te cobalt ngota nui (Pikitia 2c). Heoi, ko ngā ngota cobalt marara ngota anake i kitea i runga i te tautoko o ngā tauira e rua atu (Pikitia S9). Ko te whakaahua HAADF-STEM mā te tirotiro pūngao marara (EDS) e whakaatu ana i te tohatoha ōrite o te C, N, Co me ngā Co NP wehea i roto i ngā Co-SA/NPs@NC-950 (Pikitia 2d). E whakaatu ana ēnei hua katoa ko ngā pokapū Co marara ā-atomika me ngā matūriki nano kua whakakīia ki roto i te waro rite-karapa kua tāpirihia ki te N kua honoa angitu ki ngā papa NC i roto i ngā Co-SA/NPs@NC-950, engari ko ngā pokapū konganuku wehea anake.
I tirotirohia te āhua o te uara me te hanganga matū o ngā rauemi i whiwhihia mā te mātakitaki irahiko whakaahua hihi-X (XPS). I whakaatuhia e ngā irahiko XPS o ngā whakakorikori e toru te aroaro o ngā huānga Co, N, C me O, engari ko te Zn anake i kitea i roto i ngā Co-SA/NPs@NC-850 me ngā Co-SA/NPs@NC-750 (Pikitia 2). ). C10). I te pikinga o te pāmahana pyrolysis, ka heke te ihirangi hauota katoa i te mea ka noho pūmau ngā momo hauota ka pirau ki ngā hau NH3 me NOx i ngā pāmahana teitei ake (Ripanga S4) 47. Nō reira, ka piki haere te ihirangi waro katoa mai i ngā Co-SA/NPs@NC-750 ki ngā Co-SA/NPs@NC-850 me ngā Co-SA/NPs@NC-950 (Pikitia S11 me S12). He iti ake te ōwehenga o ngā ngota hauota o te tauira i pyrolyzed i te pāmahana teitei ake, ko te tikanga me iti iho te nui o ngā kaikawe NC i roto i ngā Co-SA/NPs@NC-950 i ērā o ētahi atu tauira. Ka hua ake tēnei i te kaha ake o te sintering o ngā matūriki cobalt. E whakaatu ana te whānuitanga O 1s i ngā tihi e rua, arā, ko C=O (531.6 eV) me C–O (533.5 eV), ia (Pikitia S13) 48. E ai ki te Pikitia 2a, ka taea te wehewehe i te whānuitanga N 1s ki ngā tihi āhuatanga e whā o te hauota pyridine N (398.4 eV), te pyrrole N (401.1 eV), te graphite N (402.3 eV) me te Co-N (399.2 eV). Kei roto i ngā tauira e toru ngā here Co-N, e tohu ana kei te hono ētahi ngota N ki ngā pae monometallic, engari he rerekē rawa ngā āhuatanga49. Mā te whakamahi i te pāmahana pyrolysis teitei ake ka taea te whakaiti i te ihirangi o ngā momo Co-N mai i te 43.7% i roto i te Co-SA/NPs@NC-750 ki te 27.0% i roto i te Co-SAs/NPs@NC-850 me te Co 17.6%@ NC-950. i roto i ngā -CA/NP, e rite ana ki te pikinga o te ihirangi C (Pikitia 3a), e tohu ana ka taea te huri i tā rātou tau whakaritenga Co-N me te whakakapia wāhanga e ngā ngota C50. E whakaatu ana te whānuitanga Zn 2p kei te noho nui tēnei huānga i te āhua Zn2+. (Pikitia S14) 51. E whakaatu ana te whānuitanga o te Co 2p i ngā tihi e rua e kitea nuitia ana i te 780.8 me te 796.1 eV, e pā ana ki te Co 2p3/2 me te Co 2p1/2, ia (Pikitia 3b). Ki te whakatauritea ki ngā Co-SA/NPs@NC-850 me ngā Co-SAs/NPs@NC-750, ka nekehia te tihi Co-N i roto i ngā Co-SAs/NPs@NC-950 ki te taha pai, e tohu ana he nui ake te whakahekenga irahiko o te ngota Co kotahi ki te mata -SAs/NPs@NC-950, ka hua ake he āhua waikura teitei ake. He mea tika kia mōhiotia ko ngā Co-SA/NPs@NC-950 anake i whakaatu i te tihi ngoikore o te cobalt kore-valent (Co0) i te 778.5 eV, e whakaatu ana i te noho o ngā matūriki nano i puta mai i te whakakotahitanga o te cobalt SA i ngā pāmahana teitei.
a Ngā hihi N 1s me b Ngā hihi Co 2p o Co-SA/NPs@NC-T. c Ngā hihi XANES me d Ngā hihi FT-EXAFS o te taha-Co-K o Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850 me Co-SAs/NPs@NC-750. e Ngā kauwhata āhua WT-EXAFS o Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850, me Co-SAs/NPs@NC-750. f Te pihi taunga FT-EXAFS mō Co-SA/NPs@NC-950.
I whakamahia te whakamātautau mimiti hihi-X kua maukati-wā (XAS) hei tātari i te hanganga hiko me te taiao taunga o te momo Co i roto i te tauira kua whakaritea. Ko ngā āhua o te korōtā i roto i te Co-SAs/NPs@NC-950, Co-SAs/NPs@NC-850 me te Co-SAs/NPs@NC-750 i whakaatuhia te hanganga taha e te mimiti hihi-X tata-papa kua whakatauritea i te taha Co-K (XANES). E ai ki te whakaaturanga i te Pikitia 3c, ko te mimiti tata ki te taha o ngā tauira e toru kei waenganui i ngā pepa Co me CoO, e tohu ana ko te āhua korōtā o ngā momo Co kei waenga i te 0 ki te +253. Hei tāpiri, i kitea he whakawhiti ki te pūngao iti iho i te Co-SAs/NPs@NC-950 ki te Co-SAs/NPs@NC-850 me te Co-SAs/NPs@NC-750, e tohu ana he iti ake te āhua waikura o te Co-SAs/NPs@NC-750. Te raupapa whakamuri. E ai ki ngā hua o te taunga whakakotahitanga rārangi, ko te āhua o te Co valence o Co-SAs/NPs@NC-950 e kiia ana he +0.642, he iti iho i te āhua o te Co valence o Co-SAs/NPs@NC-850 (+1.376). Co-SA/NP @NC-750 (+1.402). E whakaatu ana ēnei hua kua tino heke te āhua waikura toharite o ngā matūriki cobalt i roto i ngā Co-SAs/NPs@NC-950, he rite ki ngā hua XRD me HADF-STEM, ā, ka taea te whakamārama mā te noho tahi o ngā matūriki nano cobalt me ​​te cobalt takitahi. Ngā ngota Co 41. E whakaatu ana te whānuitanga hanganga pai mimiti hihi-X o te huringa Fourier (FT-EXAFS) o te taha-Co K ko te tihi matua i te 1.32 Å nō te anga Co-N/Co-C, ko te ara marara o te Co-Co whakarewa kei te 2.18 anake i roto i ngā Co-SA Å i kitea i roto i te /NPs@NC-950 (Pikitia 3d). Haunga tēnā, e whakaatu ana te kauwhata āhua huringa ngaru (WT) i te kaha mōrahi i te 6.7 Å-1 i honoa ki te Co-N/Co-C, ko ngā Co-SA/NPs@NC-950 anake e whakaatu ana i te kaha mōrahi i honoa ki te 8.8. Ko tētahi atu kaha mōrahi kei te Å−1 ki te here Co–Co (Pikitia 3e). Hei tāpiritanga, i whakaatuhia e te tātaritanga EXAFS i mahia e te kairihi i ngā pāmahana pyrolysis o te 750, 850 me te 950 °C, ko ngā tau taunga Co-N he 3.8, 3.2 me te 2.3, ia, ā, ko ngā tau taunga Co-C he 0. 0.9 me te 1.8 (Pikitia 3f, S15 me te Ripanga S1). Ina koa, ko ngā hua hou ka taea te kī ko te aroaro o ngā waeine CoN2C2 me ngā matūriki nano kua mararahia i roto i ngā Co-SA/NPs@NC-950. He rerekē, i roto i ngā Co-SA/NPs@NC-850 me ngā Co-SA/NPs@NC-750, ko ngā waeine CoN3C me CoN4 anake kei reira. He mārama kei te piki haere te pāmahana pyrolysis, ka whakakapia haeretia ngā ngota N i roto i te waeine CoN4 e ngā ngota C, ā, ka huihui ngā cobalt CA hei hanga i ngā matūriki nano.
I whakamahia ngā āhuatanga tauhohenga i akohia i mua hei ako i te pānga o ngā āhuatanga whakarite ki ngā āhuatanga o ngā rauemi rerekē (Pikitia S16)17,49. E ai ki te Pikitia 4 a, he nui ake te mahi a ngā Co-SA/NPs@NC-950 i tērā o ngā Co-SA/NPs@NC-850 me ngā Co-SA/NPs@NC-750. He mea nui, ko ngā tauira Co e toru i whakaritea i whakaatu i te mahi pai ake i te whakataurite ki ngā whakakorikori konganuku utu nui arumoni paerewa (Pd/C me Pt/C). Hei tāpiri, kāore ngā tauira Zn-ZIF-8 me Zn-NC i te mahi ki te tango waikawa formic, e tohu ana ehara ngā matūriki Zn i ngā pae mahi, engari he iti noa iho te pānga ki te mahi. Hei tāpiri, i pāngia te mahi a ngā Co-SA/NPs@NC-850 me ngā Co-SA/NPs@NC-750 e te pyrolysis tuarua i te 950°C mō te 1 hāora, engari he iti iho i tērā o ngā Co-SA/NPs@NC-750. @NC-950 (Pikitia S17). I whakaatuhia e te āhua hanganga o ēnei rauemi te aroaro o ngā matūriki nano Co i roto i ngā tauira i whakapūkaratia anō, engari ko te iti o te horahanga mata motuhake me te kore o te waro rite ki te karāhe i hua ake ai he iti ake te mahi ki te whakataurite ki ngā Co-SA/NPs@NC-950 (Pikitia S18–S20). I whakaritea hoki te mahi a ngā tauira me ngā rahinga rerekē o te mua o te Co, me te mahi teitei rawa i whakaaturia i te tāpiri 3.5 mol (Ripanga S6 me te Pikitia S21). He mārama ko te hanganga o ngā pokapū whakarewa rerekē e pāngia ana e te ihirangi hauwai i roto i te hau whakapūkara me te wā whakapūkara. Nō reira, i aromatawaihia ētahi atu rauemi Co-SA/NPs@NC-950 mō te mahi tango hauwai waikawa formic. I whakaatu ngā rauemi katoa i te mahi ngawari ki te tino pai; heoi, kāore tetahi o rātou i pai ake i ngā Co-SA/NPs@NC-950 (Pikitia S22 me S23). I whakaatuhia e te āhuatanga hanganga o te rauemi, me te piki haere o te wā whakapūkara, ka heke haere te ihirangi o ngā tūranga Co-N monoatomic nā te whakakotahitanga o ngā ngota konganuku ki roto i ngā matūriki nano, e whakamārama ana i te rerekētanga o te ngohe i waenga i ngā tauira me te rerekētanga o te wā whakapūkara o te 100-2000. (Pikitia S24–S28 me te Ripanga S7).
Kauwhata o te rōrahi hau me te wā i whiwhihia i te wā e tangohia ana te hauwai o ngā huihuinga wahie mā te whakamahi i ngā momo whakakorikori. Ngā āhuatanga tauhohenga: PC (10 mmol, 377 μl), whakakorikori (30 mg), PC (6 ml), Tback: 110 °C, Tactical: 98 °C, 4 wāhanga b Co-SAs/NPs@NC-950 (30 mg), ngā momo whakarewa. c Whakataurite i ngā tere whanaketanga hau o ngā whakakorikori kanorau i roto i ngā whakarewa waro i te 85–110 °C. d Whakamātautau hangarua Co-SA/NPs@NC-950. Ngā āhuatanga tauhohenga: FA (10 mmol, 377 µl), Co-SAs/NPs@NC-950 (30 mg), whakarewa (6 ml), Tset: 110 °C, Tactual: 98 °C, kotahi te haora te roa o ia huringa tauhohenga. Ko ngā pae hapa e tohu ana i ngā paerewa rerekētanga i tatauhia mai i ngā whakamātautau hohe e toru.
I te nuinga o te wā, ko te whai huatanga o ngā whakakorikori tango-hauwai FA e tino whakawhirinaki ana ki ngā āhuatanga tauhohenga, inā koa te whakarewa i whakamahia8,49. I te whakamahinga o te wai hei whakarewa, ko ngā Co-SAs/NPs@NC-950 te mea i whakaatu i te tere tauhohenga tuatahi teitei rawa atu, engari i puta te whakakorenga, nā te mea pea i noho ngā protons, H2O18 rānei i ngā pae hohe. Ko te whakamātautau i te whakakorikori i roto i ngā whakarewa waro pēnei i te 1,4-dioxane (DXA), n-butyl acetate (BAC), toluene (PhMe), triglyme me te cyclohexanone (CYC) kāore hoki i whakaatu i tētahi whakapainga, ā, i roto i te propylene carbonate (PC)) (Pikitia 4b me te Ripanga S8). Waihoki, ko ngā tāpiringa pēnei i te triethylamine (NEt3) te konutai formate rānei (HCCONa) kāore he pānga pai atu ki te mahi whakakorikori (Pikitia S29). I raro i ngā āhuatanga tauhohenga tino pai, i eke te hua hau ki te 1403.8 mL g−1 h−1 (Pikitia S30), he nui ake i ngā whakakorikori Co katoa i pūrongohia i mua (tae atu ki a SAC17, 23, 24). I roto i ngā whakamātautau maha, i te korenga o ngā tauhohenga i roto i te wai me ngā tāpiringa formate, i whiwhihia ngā kōwhiringa tango hauwai me te tango wai tae atu ki te 99.96% (Ripanga S9). Ko te pūngao whakahohe i tatauhia ko te 88.4 kJ/mol, he rite ki te pūngao whakahohe o ngā whakakorikori konganuku rangatira (Pikitia S31 me te Ripanga S10).
Hei tāpiritanga, i whakaritea e mātou ētahi atu whakakorikori rerekē mō te tango waikawa formic i raro i ngā āhuatanga ōrite (Pikitia 4c, ngā ripanga S11 me te S12). E ai ki te Pikitia 3c, ko te tere whakaputa hau o Co-SAs/NPs@NC-950 he nui ake i te nuinga o ngā whakakorikori konganuku turanga rerekē e mōhiotia ana, ā, he 15 me te 15 ngā wā teitei ake i te 5% Pd/C arumoni me te 5% Pd/C, ia, mā te 10 kotahi. % whakakorikori Pt/C.
Ko tētahi āhuatanga nui o tētahi whakamahinga mahi o ngā whakakōkī (whakakore)hauwai ko tōna pumau. Nō reira, i whakahaerehia he raupapa whakamātautau hangarua mā te whakamahi i ngā Co-SA/NPs@NC-950. E ai ki te whakaaturanga i te Pikitia 4 d, kāore i rerekē te mahi tuatahi me te whiriwhiringa o te rauemi mō ngā oma e rima karapīpiti (tirohia hoki te Ripanga S13). I whakahaerehia ngā whakamātautau roa, ā, i piki haere te hanga hau i roto i ngā haora 72 (Pikitia S32). Ko te ihirangi cobalt o te Co-SA/NPs@NC-950 i whakamahia he 2.5 wt%, he tino tata ki te ihirangi o te whakakōkī hou, e tohu ana kāore he rerenga mārama o te cobalt (Ripanga S14). Kāore i kitea he huringa tae mārama, he huihuinga rānei o ngā matūriki whakarewa i mua me muri i te tauhohenga (Pikitia S33). Ko te AC-HAADF-STEM me te EDS o ngā rauemi i whakamahia i roto i ngā whakamātautau roa i whakaatu i te pupuri me te horapa ōrite o ngā pae horapa ngota, ā, kāore he huringa hanganga nui (Pikitia S34 me S35). Kei te noho tonu ngā tihi āhuatanga o te Co0 me te Co-N i roto i te XPS, e whakaatu ana i te noho tahi o ngā Co NP me ngā pae whakarewa takitahi, e whakaū ana hoki i te pumau o te whakakorikori Co-SAs/NPs@NC-950 (Pikitia S36).
Hei tautuhi i ngā pae tino hohe e kawenga ana mō te tangohanga waikawa formic, i whakaritea ngā rauemi kua tīpakohia he kotahi anake te pokapū whakarewa (CoN2C2) Co NP rānei i runga i ngā rangahau o mua17. Ko te raupapa o te ngohe tangohanga waikawa formic i kitea i raro i ngā āhuatanga ōrite ko Co-SAs/NPs@NC-950 > Co SA > Co NP (Ripanga S15), e tohu ana he kaha ake ngā pae CoN2C2 kua mararahia i roto i te ngota i ngā NP. E whakaatu ana te kinetics tauhohenga ko te whanaketanga hauwai e whai ana i te kinetics tauhohenga tuatahi, engari kāore i te ōrite ngā pari o ētahi kōpiko i ngā ihirangi cobalt rerekē, e tohu ana ko te kinetics kāore i te whakawhirinaki ki te waikawa formic anake, engari ki te pae hohe hoki (Pikitia 2). C37). I whakaatuhia e ngā rangahau kinetics anō, i te mea kāore he tihi whakarewa cobalt i roto i te tātaritanga diffraction X-ray, ko te raupapa kinetic o te tauhohenga e pā ana ki te ihirangi cobalt i kitea he 1.02 i ngā taumata iti iho (iti iho i te 2.5%), e tohu ana i te tohatoha tata ōrite o ngā pokapū cobalt monoatomic. matua. pae hohe (pikitia S38 me S39). Ina eke te ihirangi o ngā matūriki Co ki te 2.7%, ka piki ohorere te r, e tohu ana he pai te taunekeneke a ngā matūriki nano ki ngā ngota takitahi kia nui ake ai te mahi. I te piki haere tonu o te ihirangi o ngā matūriki Co, ka kore e raina te pihi, e pā ana ki te pikinga o te maha o ngā matūriki nano me te hekenga o ngā tūranga monatomic. Nō reira, ko te whakapainga o te mahi tango hauwai LC o Co-SA/NPs@NC-950 ka puta mai i te whanonga mahi tahi o ngā pae whakarewa takitahi me ngā matūriki nano.
I whakahaerehia he rangahau hōhonu mā te whakamahi i te in situ diffuse reflectance Fourier transform (in situ DRIFT) hei tautuhi i ngā takawaenga tauhohenga i roto i te tukanga. I muri i te whakamahana i ngā tauira ki ngā pāmahana tauhohenga rerekē i muri i te tāpiri i te waikawa formic, e rua ngā huinga auau i kitea (Pikitia 5a). E toru ngā tihi āhuatanga o te HCOOH* ka puta i te 1089, 1217 me te 1790 cm-1, e pā ana ki te wiri totoro CH π (CH) i waho o te papa, te wiri totoro CO ν (CO) me te wiri totoro C=O ν (C=O), 54, 55 ia. Ko tētahi atu huinga tihi i te 1363 me te 1592 cm-1 e rite ana ki te wiri OCO ōrite νs(OCO) me te wiri totoro OCO kore ōrite νas(OCO)33.56 HCOO*, ia. I te haere tonu o te tauhohenga, ka memeha haere ngā tihi whanaunga o te momo HCOOH* me te HCOO*. I te nuinga o te wā, e toru ngā taahiraa matua o te wetewete o te waikawa formic: (I) te mimiti o te waikawa formic ki ngā pae hohe, (II) te tango i te H mā te ara formate, carboxylate rānei, me te (III) te whakakotahitanga o ngā H e rua kua mimitihia hei whakaputa hauwai. Ko te HCOO* me te COOH* ngā takawaenga matua hei whakatau i ngā ara formate, carboxylate rānei, ia. 57. Mā te whakamahi i tā mātou pūnaha whakatere, ko te tihi HCOO* āhuatanga anake i puta, e tohu ana ko te wetewete waikawa formic ka puta noa mā te ara waikawa formic58. I kitea anō ngā kitenga rite i ngā pāmahana iti iho o te 78 °C me te 88 °C (pikitia S40).
Ngā ira DRIFT in situ o te tangohanga HCOOH i runga i te Co-SAs/NPs@NC-950 me te b Co SAs. E tohu ana te kōrero i ngā wā tauhohenga i te wāhi. c Te rerekētanga o te rōrahi hau i hangaia mā te whakamahi i ngā tauhohenga tapanga isotope rerekē i roto i te wā. d Ngā raraunga pānga isotope kinetic.
I whakahaerehia ngā whakamātautau DRIFT in situ rite tonu ki ngā rauemi e pā ana, arā, ko Co NP me Co SA hei ako i te pānga mahi tahi i roto i te Co-SA/NPs@NC-950 (Pikitia 5 b me S41). E whakaatu ana ngā rauemi e rua i ngā au rite tonu, engari he paku neke ngā tihi āhuatanga o te HCOOH* me te HCOO*, e tohu ana ko te whakaurunga o ngā Co NP ka huri i te hanganga hiko o te pokapū monoatomic. Ka puta he tihi āhuatanga νas(OCO) i roto i ngā Co-SA/NPs@NC-950 me te Co SA engari kāore i roto i ngā Co NP, e tohu ana anō ko te takawaenga i hangaia i te tāpiritanga o te waikawa formic he waikawa formic monodentate e poutū ana ki te mata tote papa. ā, ka piri ki runga i te SA hei pae hohe 59. He mea tika kia mōhiotia i kitea he pikinga nui o ngā wiri o ngā tihi āhuatanga π(CH) me ν(C = O), i puta ai te whakapōturitanga o te HCOOH*, ā, i āwhina i te tauhohenga. Nā reira, tata ngaro ngā tihi āhua o te HCOOH* me te HCOO* i roto i ngā Co-SA/NPs@NC i muri i te 2 meneti o te tauhohenga, he tere ake tēnei i te tere o ngā whakakorikori monometallic (6 meneti) me ngā whakakorikori nanoparticle (12 meneti). . E whakaū ana ēnei hua katoa ka whakarei ake te tāpiritanga nanoparticle i te mimiti me te whakahohenga o ngā takawaenga, ā, ka tere ake ngā tauhohenga kua whakaarohia i runga ake nei.
Hei tātari atu i te ara tauhohenga me te whakatau i te taahiraa whakatau tere (RDS), i whakahaerehia te pānga KIE i te aroaro o ngā Co-SAs/NPs@NC-950. I konei, ka whakamahia ngā momo isotopes waikawa formic pērā i te HCOOH, HCOOD, DCOOH me te DCOOD mō ngā rangahau KIE. E ai ki te Whakaahua 5c, ka heke te tere dehydrogenation i te raupapa e whai ake nei: HCOOH > HCOOD > DCOOH > DCOOD. Hei tāpiri, ko ngā uara o KHCOOH/KHCOOD, KHCOOH/KDCOOH, KHCOOD/KDCOOD me KDCOOH/KDCOOD i tatauhia ko 1.14, 1.71, 2.16 me 1.44, ia (Pikitia 5d). Nō reira, ko te wehenga o te hononga CH i roto i te HCOO* e whakaatu ana i ngā uara kH/kD neke atu i te 1.5, e tohu ana i tētahi pānga nekeneke nui60,61, ā, te āhua nei ko te RDS o te tangohanga hauwai o te HCOOH i runga i ngā Co-SA/NPs@NC-950.
Hei tāpiritanga, i whakahaerehia ngā tātaitanga DFT hei mārama ki te pānga o ngā matūriki nano kua tāpirihia ki te mahi ā-roto o Co-SA. I hangaia ngā tauira Co-SA/NPs@NC me Co-SA i runga i ngā whakamātautau i whakaaturia me ngā mahi o mua (Pikitia 6a me S42)52,62. Whai muri i te arotautanga āhuahanga, i tautuhia ngā matūriki nano Co6 iti (CoN2C2) e noho tahi ana me ngā waeine monoatomic, ā, i whakatauhia ko te roa o te here Co-C me Co-N i roto i te Co-SA/NPs@NC he 1.87 Å me te 1.90 Å, ia. , e rite ana ki ngā hua XAFS. Ko te kiato wāhanga o ngā āhua (PDOS) i tatauhia e whakaatu ana ko te ngota konganuku Co kotahi me te hiato matūriki nano (Co-SAs/NPs@NC) e whakaatu ana i te whakaranu teitei ake tata ki te taumata Fermi ki te whakataurite ki te CoN2C2, ka hua ake ko te HCOOH. He pai ake te whakawhiti irahiko kua pakaru (Pikitia 6b me S43). I tatauhia ngā pokapū d-band e rite ana o Co-SAs/NPs@NC me Co-SA ki te -0.67 eV me te -0.80 eV, ia, i roto i ēnei ko te pikinga o Co-SAs/NPs@NC he 0.13 eV, ā, i whai wāhi mai i muri i te whakaurunga o NP, ka puta te mimiti o ngā matūriki HCOO* e te hanganga hiko kua whakarerekētia o CoN2C2. Ko te rerekētanga o te kiato utu e whakaatu ana i te kapua irahiko nui huri noa i te poraka CoN2C2 me te matūriki nano, e tohu ana i te taunekeneke kaha i waenganui i a rātou nā te whakawhiti irahiko. I te whakakotahitanga me te tātari utu Bader, i kitea ko te Co kua mararahia i roto i te atomic i ngaro te 1.064e i roto i te Co-SA/NPs@NC me te 0.796e i roto i te Co SA (Pikitia S44). E tohu ana ēnei hua ko te whakaurunga o ngā matūriki nano ka arahi ki te whakaiti irahiko o ngā pae Co, ka hua ake he pikinga o te uara Co, he rite ki ngā hua XPS (Pikitia 6c). I tātarihia ngā āhuatanga taunekeneke Co-O o te mimiti HCOO ki runga i ngā Co-SA/NPs@NC me te Co SA mā te tatau i te rōpū Hamiltonian porowhita tioata (COHP)63. E ai ki te whakaaturanga i te Pikitia 6 d, ko ngā uara kino me ngā uara pai o te -COHP e rite ana ki te āhua ārai-hononga me te āhua here. I aromatawaihia te kaha here o te Co-O i mimitihia e te HCOO (Co-carbonyl O HCOO*) mā te whakauru i ngā uara -COHP, arā, 3.51 me te 3.38 mō ngā Co-SA/NPs@NC me te Co-SA. I whakaatuhia hoki ngā hua ōrite o te mimiti HCOOH: ko te pikinga o te uara whakauru o te -COHP i muri i te tāpiritanga nanoparticle e tohu ana i te pikinga o te here Co-O, ā, nā reira ka whakatairanga i te whakahohenga o te HCOO me te HCOOH (Pikitia S45).
Hanganga whatunga Co-SA/NPs@NC-950. b PDOS Co-SA/NP@NC-950 me Co SA. c Mata iso3D o te rerekētanga o ngā mātotoru utu o te mimiti HCOOH ki runga i te Co-SA/NPs@NC-950 me te Co-SA. (d) pCOHP o ngā here Co-O i mimitihia e te HCOO ki runga i te Co-SA/NPs@NC-950 (maui) me te Co-SA (matau). e Ara tauhohenga o te tangohanga hauwai HCOOH ki runga i te Co-SA/NPs@NC-950 me te Co-SA.
Hei mārama ake i te mahi tango hauwai pai rawa atu o Co-SA/NPs@NC, i whakatauhia te ara tauhohenga me te pūngao. Ina koa, e rima ngā taahiraa o te tango hauwai FA, tae atu ki te hurihanga o te HCOOH ki te HCOOH*, te HCOOH* ki te HCOO* + H*, te HCOO* + H* ki te 2H* + CO2*, te 2H* + CO2* ki te 2H* + CO2, me te 2H* i roto i te H2 (Pikitia 6e). Ko te pūngao mimiti o ngā ngota waikawa formic i runga i te mata o te whakakorikori mā te hāora carboxylic he iti iho i te mā te hāora hydroxyl (Pikitia S46 me te S47). Nō muri mai, nā te iti o te pūngao, ka pai ake te pakaru o te hononga OH o te kaimomo hei hanga i te HCOO* kaua ki te pakaru o te hononga CH hei hanga i te COOH*. I taua wā anō, ka whakamahia e te HCOO* te mimiti monodentate, e whakatairanga ana i te pakaru o ngā hononga me te hanganga o te CO2 me te H2. He rite tonu ēnei hua ki te aroaro o te tihi νas(OCO) i roto i te in situ DRIFT, e tohu ana anō ka puta te whakahekenga FA mā te ara formate i roto i tā mātou rangahau. He mea nui kia mōhiotia, e ai ki ngā inenga KIE, he nui ake te arai pūngao tauhohenga o te wehenga CH i ngā taahiraa tauhohenga kē atu, ā, e tohu ana i te RDS. Ko te arai pūngao o te pūnaha whakakorikori Co-SAs/NPs@NC tino pai he 0.86 eV te iti iho i te Co-SA (1.2 eV), e whakapai ake ana i te whai huatanga o te tango hauwai whānui. He mea nui, ko te aroaro o ngā matūriki nano e whakahaere ana i te hanganga hiko o ngā pae honohono kua mararahia e te ngota, e whakarei ake ana i te mimiti me te whakahohenga o ngā takawaenga, ā, ka whakaiti i te arai tauhohenga me te whakatairanga i te hanga hauwai.
Hei whakarāpopototanga, ka whakaaturia e mātou mō te wā tuatahi ka taea te whakapai ake i te mahi whakatere o ngā whakatere hanga hauwai mā te whakamahi i ngā rauemi he pokapū monometallic tino tohatoha me ngā nanoparticles iti. Kua whakamanahia tēnei ariā e te hanganga o ngā whakatere konganuku kotahi-te-kobalt i whakarerekētia ki ngā nanoparticles (Co-SAs/NPs@NC), me ngā rauemi e pā ana me ngā pokapū konganuku kotahi anake (CoN2C2) me ngā Co NP rānei. I whakaritea ngā rauemi katoa mā te tikanga pyrolysis kotahi-taahiraa ngāwari. E whakaatu ana te tātari hanganga ko te whakatere pai rawa atu (Co-SAs/NPs@NC-950) he mea hanga mai i ngā waeine CoN2C2 kua mararahia e te ngota me ngā nanoparticles iti (7-8 nm) kua tāpirihia ki te hauota me te waro rite ki te karāhe. He pai rawa te hua hau tae atu ki te 1403.8 ml g-1 h-1 (H2:CO2 = 1.01:1), H2 me te whiriwhiringa CO o te 99.96% ā, ka taea te pupuri i te mahi tonu mō ētahi rā. E 4 me te 15 ngā wā e nui ake ai te mahi a tēnei whakakorikori i te mahi a ētahi whakakorikori Co SA me Pd/C. E whakaatu ana ngā whakamātautau DRIFT in situ, ki te whakaritea ki te Co-SA, he kaha ake te mimiti monodentate o te HCOO* e whakaatuhia ana e ngā Co-SA/NPs@NC-950, he mea nui tēnei mō te ara formate, ā, ka taea e ngā matūriki nano dopant te whakatairanga i te whakahohenga HCOO* me te whakaterenga C–H. I tautuhia te wehenga hononga hei RDS. E whakaatu ana ngā tātaitanga ariā ka whakanuia e te tāpiringa Co NP te pokapū d-band o ngā ngota Co takitahi mā te 0.13 eV mā te taunekeneke, ka whakarei ake i te mimiti o ngā takawaenga HCOOH* me HCOO*, ā, ka whakaitihia te arai tauhohenga mai i te 1.20 eV mō Co SA ki te 0 .86 eV. Ko ia te kawenga mō te mahi tino pai.
I te whānui ake, ka whakaratohia e tēnei rangahau ngā whakaaro mō te hoahoa i ngā whakakorikori konganuku kotahi-ngota hou, ā, ka whakatairanga i te māramatanga me pēhea te whakapai ake i te mahi whakakorikori mā te pānga tahi o ngā pokapū konganuku o ngā rahi rerekē. E whakapono ana mātou ka taea te whakawhānui ake i tēnei huarahi ki te maha atu o ngā pūnaha whakakorikori.
I hokona mai i McLean, Haina te Co(NO3)2 6H2O (AP, 99%), Zn(NO3)2 6H2O (AP, 99%), 2-methylimidazole (98%), methanol (99.5%), propylene carbonate (PC, 99%) ethanol (AR, 99.7%). I hokona mai i Rhawn, Haina te waikawa formic (HCOOH, 98%). I whakamahia tika ngā matū katoa me te kore he purenga tāpiri, ā, i whakaritea te wai tino parakore mā te whakamahi i tētahi pūnaha purenga tino parakore. I hokona mai i Sigma-Aldrich te Pt/C (5% te utaina papatipu) me te Pd/C (5% te utaina papatipu).
I whakahaerehia te hanganga o ngā nanocrystals CoZn-ZIF i runga i ngā tikanga o mua me ētahi whakarerekētanga23,64. Tuatahi, i konatunatuahia te 30 mmol Zn(NO3)2·6H2O (8.925 g) me te 3.5 mmol Co(NO3)2·6H2O (1.014 g) ka whakarewahia ki roto i te 300 ml o te methanol. Kātahi ka whakarewahia te 120 mmol o te 2-methylimidazole (9.853 g) ki roto i te 100 ml o te methanol ka tāpirihia ki te otinga i runga ake nei. I whakaohokia te ranunga i te pāmahana rūma mō ngā haora 24. Hei whakamutunga, i wehea te hua mā te centrifugation i te 6429 g mō te 10 meneti ka horoia pai ki te methanol e toru ngā wā. I whakamaroketia te paura hua i roto i te korehau i te 60°C i te pō i mua i te whakamahinga.
Hei hanga i ngā Co-SA/NPs@NC-950, i whakapūkarahia te paura CoZn-ZIF maroke ki te 950 °C mō te 1 hāora i roto i te rere hau o te 6% H2 + 94% Ar, me te tere whakamahana o te 5 °C/min. Kātahi ka whakamataohia te tauira ki te pāmahana rūma hei whiwhi i te Co-SA/NPs@NC-950. Mō ngā Co-SA/NPs@NC-850, Co-SAs/NPs@NC-750 rānei, i whakarerekētia te pāmahana whakapūkara ki te 850 me te 750 °C. Ka taea te whakamahi i ngā tauira kua oti te whakarite me te kore e tukatukahia anō, pērā i te keri waikawa.
I whakahaerehia ngā inenga TEM (whakamātautau hiko tuku) i runga i tētahi karu hiko "cube" Thermo Fisher Titan Themis 60-300 kua rite ki tētahi whakatikatika hapa ahua me tētahi karāhe hanga probe 300 kV. I whakahaerehia ngā whakamātautau HAADF-STEM mā te whakamahi i ngā karu hiko FEI Titan G2 me FEI Titan Themis Z kua rite ki ngā probe me ngā whakatikatika ahua, me ngā pūoko wāhanga-whā DF4. I whiwhihia hoki ngā whakaahua mahere huānga EDS i runga i tētahi karu hiko FEI Titan Themis Z. I whakahaerehia te tātaritanga XPS i runga i tētahi ine irahiko whakaahua hihi-X (tauira Thermo Fisher ESCALAB 250Xi). I kohia ngā ira XANES me EXAFS Co K-edge mā te whakamahi i tētahi ripanga XAFS-500 (China Spectral Instruments Co., Ltd.). I whakatauhia te ihirangi Co mā te ine mimiti ngota (AAS) (PinAAcle900T). I tuhia ngā irahiko X-ray diffraction (XRD) ki runga i te X-ray diffractometer (Bruker, Bruker D8 Advance, Tiamana). I whiwhihia ngā isotherm adsorption hauota mā te whakamahi i tētahi taputapu adsorption ā-tinana (Micromeritics, ASAP2020, USA).
I whakahaerehia te tauhohenga tango hauwai i roto i te hau argon me te hau i tangohia e ai ki te tikanga paerewa Schlenk. I tangohia te ipu tauhohenga, ā, i whakakīia ki te argon e 6 ngā wā. Whakakāhia te puna wai whakapūmau, ka tāpirihia he whakakorikori (30 mg) me te whakarewa (6 ml). Whakamahanahia te ipu ki te pāmahana e hiahiatia ana mā te whakamahi i te thermostat, ā, tukua kia taurite mō te 30 meneti. Kātahi ka tāpirihia te waikawa formic (10 mmol, 377 μL) ki te ipu tauhohenga i raro i te argon. Tahurihia te takirere pūrere toru-ara hei whakaiti i te pēhanga o te tauhohenga, katia anō, ka tīmata te ine i te rōrahi o te hau i hangaia mā te whakamahi i te pūrere ā-ringa (Pikitia S16). I muri i te wā e hiahiatia ana mō te otinga o te tauhohenga, i kohia he tauira hau mō te tātari GC mā te whakamahi i te ngira hau-kī kua horoia ki te argon.
I whakahaerehia ngā whakamātautau DRIFT in situ i runga i tētahi inenga Fourier transform infrared (FTIR) (Thermo Fisher Scientific, Nicolet iS50) kua rite ki tētahi pūoko mercury cadmium telluride (MCT). I whakanohoia te paura whakakorikori ki roto i tētahi pūtau tauhohenga (Harrick Scientific Products, Praying Mantis). I muri i te rongoā i te whakakorikori ki te awa o te Ar (50 ml/min) i te pāmahana rūma, ka whakamahanahia te tauira ki tētahi pāmahana kua whakaritea, kātahi ka pupuhihia ki te Ar (50 ml/min) i roto i tētahi otinga HCOOH ka ringihia ki roto i te pūtau tauhohenga in-situ. mō te tauhohenga. Ngā tukanga whakakorikori rerekē o te tauira. I tuhia ngā inenga infrared i ngā wā mai i te 3.0 hēkona ki te 1 hāora.
Ko te HCOOH, te DCOOH, te HCOOD me te DCOOD ka whakamahia hei papa i roto i te propylene carbonate. Ko ngā āhuatanga e toe ana e rite ana ki te tukanga tango hauwai HCOOH.
I whakahaerehia ngā tataunga mātāpono tuatahi mā te whakamahi i te anga ariā mahi kiato i roto i te mōkihi tauira Vienna Ab initio (VASP 5.4.4) 65,66. I whakamahia he pūtau superunit me te mata graphene (5 × 5) me te whānuitanga whakawhiti o te 12.5 Å hei papa mō CoN2C2 me CoN2C2-Co6. I tāpirihia he tawhiti korehau neke atu i te 15 Å hei karo i te taunekeneke i waenga i ngā paparanga papa tata. Ko te taunekeneke i waenga i ngā katote me ngā irahiko ka whakaahuahia e te tikanga ngaru whakanuia kua whakamaheretia (PAW)65,67. I whakamahia te mahi whakatata whānui o te gradient (GGA) Perdue-Burke-Ernzerhof (PBE) me te whakatikatika van der Waals i whakaarohia e Grimm68,69. Ko ngā paearu huihuinga mō te pūngao me te kaha katoa ko 10−6 eV/ngota me te 0.01 eV/Å. I whakatakotoria te tapahi pūngao ki te 600 eV mā te whakamahi i te whatunga Monkhorst-Pack 2 × 2 × 1 K-point. Ko te pūmanawa rūpahu e whakamahia ana i roto i tēnei tauira kua hangaia mai i te whirihoranga hiko ki roto i te āhua C 2s22p2, te āhua N 2s22p3, te āhua Co 3d74s2, te āhua H 1 s1, me te āhua O 2s22p4. Ka tatauhia te kaha mimiti me te rerekētanga o te mātotoru irahiko mā te tango i te kaha o te āhua hau me te momo mata mai i te kaha o te pūnaha mimiti e ai ki ngā tauira mimiti, atanga rānei70,71,72,73,74. Ka whakamahia te whakatikatika kaha kore utu a Gibbs hei huri i te kaha DFT ki te kaha kore utu a Gibbs, ā, ka whakaarohia ngā takoha wiri ki te entropy me te kaha kore tohu75. I whakamahia te tikanga aranga piki-whakaahua (CI-NEB) hei rapu i te āhua whakawhiti o te tauhohenga76.
Kei roto i te tuhinga me ngā rauemi tāpiri ngā raraunga katoa i kohia mai, i tātaritatia hoki i tēnei rangahau, i ngā tuhinga rānei e wātea ana mai i te kaituhi e pā ana mēnā he tono tika. Kei te whakaratohia ngā raraunga pūtake mō tēnei tuhinga.
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