Gcwalisa leli fomu elingezansi futhi sizokuthumela i-imeyili inguqulo ye-PDF ethi “Ukuthuthukiswa kobuchwepheshe obusha bokuguqula i-carbon dioxide ibe uphethiloli owuketshezi”
I-Carbon dioxide (CO2) iwumkhiqizo wezibaso ezimbiwa phansi ezivuthayo kanye negesi ebamba ukushisa evame kakhulu, engaguqulwa ibuyiselwe ibe izinto zokubasa eziwusizo ngendlela eqhubekayo. Enye indlela ethembisayo yokuguqula ukukhishwa kwe-CO2 kube isitoko sikaphethiloli inqubo ebizwa ngokuthi ukuncishiswa kwe-electrochemical. Kodwa ukuze ikwazi ukuhweba, inqubo idinga ukuthuthukiswa ukuze kukhethwe noma kukhiqizwe imikhiqizo efiselekayo ecebile ngekhabhoni. Manje, njengoba kubikiwe kumagazini we-Nature Energy, i-Lawrence Berkeley National Laboratory (i-Berkeley Lab) isungule indlela entsha yokuthuthukisa ubuso be-catalyst yethusi esetshenziselwa ukusabela okusizayo, ngaleyo ndlela ikhulise ukukhetha kwenqubo.
"Nakuba siyazi ukuthi ithusi liyi-catalyst engcono kakhulu yalokhu kusabela, ayinikezi ukukhetha okuphezulu komkhiqizo oyifunayo," kusho u-Alexis, usosayensi omkhulu eMnyangweni Wezesayensi Yezesayensi eBerkeley Lab kanye noprofesa wobunjiniyela bamakhemikhali eNyuvesi yaseCalifornia, eBerkeley. Kusho uSpell. "Ithimba lethu lithole ukuthi ungasebenzisa indawo yasendaweni ye-catalyst ukwenza amaqhinga ahlukahlukene ukuze unikeze lolu hlobo lokukhetha."
Ezifundweni ezedlule, abacwaningi baye basungula izimo eziqondile ukuze banikeze indawo engcono kakhulu kagesi namakhemikhali ukuze benze imikhiqizo ecebile nge-carbon enenani lezentengiselwano. Kodwa lezi zimo ziphambene nezimo ezenzeka ngokwemvelo kumangqamuzana kaphethiloli avamile asebenzisa izinto zokuqhuba ezisekelwe emanzini.
Ukuze kutholwe idizayini engasetshenziswa endaweni yamanzi yamaseli kaphethiloli, njengengxenye yephrojekthi Yesikhungo Sokuvuselela I-Energy Innovation Center ye-Liquid Sunshine Alliance yoMnyango Wezamandla, u-Bell nethimba lakhe baphendukela kungqimba oluncane lwe-ionomer, oluvumela ama-molecule athile (ama-ions) ashajiwe ukuthi adlule. Ungafaki amanye ama-ion. Ngenxa yezindawo zazo zamakhemikhali ezikhetha kakhulu, zifaneleka kakhulu ukuba nomthelela oqinile ku-microenvironment.
U-Chanyeon Kim, umcwaningi we-postdoctoral eqenjini le-Bell kanye nombhali wokuqala wephepha, uhlongoze ukuthi amboze ama-copper catalysts ngama-ionomer amabili ajwayelekile, i-Nafion ne-Sustainion. Ithimba lacabanga ukuthi ukwenza kanjalo kufanele kuguqule indawo ezungezile eduze kwe-catalyst—okuhlanganisa i-pH nenani lamanzi nesikhutha—ngandlela thize ukuze kuqondiswe ukusabela ukuze kukhiqizwe imikhiqizo ene-carbon engashintshwa kalula ibe amakhemikhali awusizo. Imikhiqizo kanye namafutha e-liquid.
Abacwaningi basebenzise ungqimba oluncane lwe-ionomer ngayinye kanye nongqimba oluphindwe kabili lwama-ionomers amabili kufilimu yethusi esekelwe yi-polymer material ukuze benze ifilimu, abangayifaka eduze komkhawulo owodwa weseli ye-electrochemical emise okwesandla. Lapho bejova i-carbon dioxide ebhethrini futhi besebenzisa i-voltage, bakala inani lamanje eligeleza ebhethrini. Babe sebelinganisa igesi noketshezi oluqoqwe endaweni yokugcina amanzi eseduze ngesikhathi sokusabela. Ngecala lezendlalelo ezimbili, bathole ukuthi imikhiqizo ene-carbon ecebile ibalwa ku-80% wamandla adliwe ukusabela-okungaphezulu kuka-60% esimweni esingenalutho.
"Le sandwich enamathela inikeza okungcono kakhulu kokubili komhlaba: ukukhetha umkhiqizo ophezulu kanye nomsebenzi ophezulu," kusho uBell. I-double-layer surface ayilungile kuphela emikhiqizweni ecebile nge-carbon, kodwa futhi ikhiqiza amandla amanje anamandla ngesikhathi esifanayo, okubonisa ukwanda komsebenzi.
Abacwaningi baphetha ngokuthi impendulo ethuthukisiwe yayiwumphumela wokuhlushwa okuphezulu kwe-CO2 okuqoqwe ekugqokeni ngqo phezulu kwethusi. Ngaphezu kwalokho, ama-molecule akhokhiswa kabi anqwabelana esifundeni phakathi kwama-ionomers amabili azokhiqiza i-asidi yendawo ephansi. Le nhlanganisela iqeda ukuhwebelana okugxilile okuvame ukwenzeka uma engekho amafilimu e-ionomer.
Ukuze kuthuthukiswe ukusebenza kahle kokusabela, abacwaningi baphendukela kubuchwepheshe obufakazelwe ngaphambilini obungadingi ifilimu ye-ionomer njengenye indlela yokwandisa i-CO2 ne-pH: i-pulsed voltage. Ngokusebenzisa i-pulsed voltage ku-double-layer ionomer coating, abacwaningi bathole ukukhuphuka okungama-250% emikhiqizweni ecebile ngekhabhoni uma kuqhathaniswa ne-copper engahlanganisiwe kanye nogesi omile.
Nakuba abanye abacwaningi begxila emsebenzini wabo ekuthuthukiseni ama-catalyst amasha, ukutholakala kwe-catalyst akunaki izimo zokusebenza. Ukulawula imvelo endaweni ye-catalyst kuyindlela entsha nehlukile.
“Asizange siqhamuke ne-catalyst entsha ngokuphelele, kodwa sasebenzisa ukuqonda kwethu i-reaction kinetics futhi sasebenzisa lolu lwazi ukuze lusiqondise ekucabangeni ukuthi singayishintsha kanjani indawo yendawo ye-catalyst,” kusho u-Adam Weber, unjiniyela omkhulu. Ososayensi abasemkhakheni wobuchwepheshe bamandla e-Berkeley Laboratories kanye nombhali-ndawonye wamaphepha.
Isinyathelo esilandelayo siwukwandisa ukukhiqizwa kwama-catalysts ahlanganisiwe. Ukuhlola kokuqala kwethimba le-Berkeley Lab kuhilela amamodeli amancane ayisicaba, abelula kakhulu kunezakhiwo ezinezimbotshana zendawo enkulu ezidingekayo ekusetshenzisweni kwezentengiso. "Akunzima ukufaka okokunamathela endaweni eyisicaba. Kodwa izindlela zokuhweba zingase zihlanganise amabhola ethusi amancane," kusho uBell. Ukwengeza ungqimba lwesibili lwe-coating kuba yinselele. Okunye okungenzeka iwukuba uhlanganise futhi ufake lezi zingubo ezimbili ndawonye entweni encibilikayo, bese uthemba ukuthi ziyahlukana lapho isincibilikisi sihwamuka. Kuthiwani uma bengakwenzi? UBell waphetha: “Kudingeka sihlakaniphe kakhudlwana.” Bheka uKim C, uBui JC, uLuo X nabanye. I-catalyst microenvironment eyenziwe ngokwezifiso yokunciphisa i-electro-CO2 emikhiqizweni enekhabhoni eminingi kusetshenziswa ungqimba oluphindwe kabili lwe-ionomer enamathela ethusi. I-Nat Energy. 2021;6(11):1026-1034. doi:10.1038/s41560-021-00920-8
Lesi sihloko senziwa kabusha kusuka kokulandelayo. Qaphela: Okubalulekile kungenzeka kuhlelwe ubude nokuqukethwe. Ukuze uthole ulwazi olwengeziwe, sicela uthinte umthombo okhonjiwe.
Isikhathi sokuthumela: Nov-22-2021
