Ukusabela kwamakhemikhali kwenzeka nxazonke zethu ngaso sonke isikhathi—kusobala uma ucabanga ngakho, kodwa bangaki kithi abakwenzayo lapho siqala imoto, sibilisa iqanda, noma sifaka umanyolo etshanini lethu?
Uchwepheshe we-Chemical Catalysis uRichard Kong ubelokhu ecabanga nge-chemical reactions. Emsebenzini wakhe njengo "unjiniyela womsindo ochwepheshe", njengoba esho yena, akanandaba nje kuphela ne-reactions ezivela kuye, kodwa futhi nokuvusa ezintsha.
Njengomfundi waseKlarman kwiKhemistri kanye neBiology yamakhemikhali eKolishi Lobuciko Nesayensi, uKong usebenza ukuthuthukisa izinto ezikhuthaza ukusabela kwamakhemikhali emiphumeleni efiselekayo, edala imikhiqizo ephephile futhi enenani elongeziwe, okuhlanganisa naleyo engaba nomthelela omuhle empilweni yomuntu. ngoLwesithathu.
“Inani elikhulu lokusabela kwamakhemikhali lenzeka ngaphandle kosizo,” kusho uKong, ebhekisela ekukhishweni kwe-carbon dioxide lapho izimoto zishisa uphethiloli. “Kodwa ukusabela kwamakhemikhali okuyinkimbinkimbi nokuyinkimbinkimbi akwenzeki ngokuzenzakalelayo. Yilapho i-catalysis yamakhemikhali iqala khona.”
UKing nozakwabo baklama i-catalyst yokuqondisa ukusabela ababekufuna, futhi kwenzeka. Isibonelo, i-carbon dioxide ingaguqulwa ibe yi-formic acid, i-methanol, noma i-formaldehyde ngokukhetha i-catalyst efanele nokuzama izimo zokusabela.
Indlela kaKong ihambisana kahle nendlela kaLancaster "eqhutshwa ukutholakala", kusho uKyle Lancaster, uprofesa we-chemistry kanye ne-chemistry biology (A&S) kanye nothisha baseKong. "URichard wayenomqondo wokusebenzisa i-tin ukuthuthukisa i-chemistry yakhe, okwakungakaze kube semibhalweni yami," kusho uLancaster. "Kuyisisusa sokuguqulwa okukhethiwe kwe-carbon dioxide ibe yinto eyigugu kakhulu, futhi i-carbon dioxide ithola ukucindezelwa okubi kakhulu."
UKing kanye nabalingani bakhe basanda kuthola uhlelo, ngaphansi kwezimo ezithile, olungaguqula i-carbon dioxide ibe yi-formic acid.
“Nakuba okwamanje singasondelene nokusabela kwesimanje, uhlelo lwethu luyakwazi ukulungiseka kakhulu,” kusho uKong. “Ngakho-ke singaqala ukuqonda ngokujulile ukuthi kungani amanye ama-catalyst esebenza ngokushesha kunezinye, ukuthi kungani amanye ama-catalyst engcono ngokwemvelo. Singakwazi ukushintsha amapharamitha ama-catalyst bese sizama ukuqonda ukuthi yini eyenza lezi zinto zisebenze ngokushesha, ngoba uma zisebenza ngokushesha, kungcono – ungakha ama-molecule ngokushesha.”
Njengomuntu waseKlarman, uKong usebenza futhi ukuguqula ama-nitrate, ubuthi obuvamile obungena emanzini, busuka endaweni ezungezile bube yinto engenangozi, usho kanje.
UKung wazama ngezinsimbi zomhlaba ezifana ne-aluminium ne-tin njengezinto ezibangela ukusha. Lezi zinsimbi zishibhile, azinabo ubuthi futhi ziningi kakhulu oqweqweni lomhlaba, ngakho ukuzisebenzisa ngeke kube nezinkinga zokusimama, kusho yena.
“Siphinde sithole ukuthi singazenza kanjani izikhuthazi lapho ezimbili zalezi zinsimbi zihlangana khona,” kusho uKong. “Ngokusebenzisa izinsimbi ezimbili ohlakeni, hlobo luni lokusabela nemibuzo ethokozisayo esingayithola ezinhlelweni ze-bimetallic?” “ukusabela kwamakhemikhali?”
Ngokusho kukaKong, i-scaffolding yindawo yamakhemikhali lapho lezi zinsimbi zihlala khona.
Eminyakeni engama-70 edlule, umkhuba ube ukusebenzisa isikhungo sensimbi esisodwa ukuze kufezwe ukuguqulwa kwamakhemikhali, kodwa eminyakeni eyishumi edlule noma ngaphezulu, osokhemisi kulo mkhakha baqale ukuhlola ukusebenzisana okusebenzisanayo phakathi kwezinsimbi ezimbili ezihlanganiswe ngamakhemikhali noma ezihambisanayo. , kusho uKong, “Kukunika amazinga engeziwe enkululeko.”
Lezi zikhuthazi ze-bimetallic zinika osokhemisi ikhono lokuhlanganisa izikhuthazi zensimbi ngokusekelwe emandleni kanye nobuthakathaka bazo, kusho uKong. Isibonelo, isikhungo sensimbi esibopha kabi i-substrate kodwa siphule izibopho kahle singasebenza nesinye isikhungo sensimbi esiphula izibopho kabi kodwa sibophe kahle i-substrate. Ukuba khona kwensimbi yesibili nakho kuthinta izakhiwo zensimbi yokuqala.
“Ungaqala ukuthola lokho esikubiza ngokuthi umphumela wokubambisana phakathi kwezikhungo ezimbili zensimbi,” kusho uKong. “Ezinye izimpendulo eziyingqayizivele nezimangalisayo ziyaqala ukuvela emkhakheni we-bimetallic catalysis.”
UKing uthe kusekhona ukungaqiniseki okukhulu mayelana nokuthi izinsimbi zihlangana kanjani ezinhlotsheni zama-molecule. Wajabula kakhulu ngobuhle bekhemistri uqobo njengoba naye ajabula ngemiphumela. UKing walethwa elabhorethri likaLancaster ngenxa yobuchwepheshe bakhe ku-X-ray spectroscopy.
“Kuyi-symbiosis,” kusho uLancaster. “I-X-ray spectroscopy yasiza uRichard ukuqonda ukuthi yini eyayingaphansi kwe-hood nokuthi yini eyenza i-tin isebenze kahle futhi ikwazi ukusabela kwamakhemikhali. Siyazuza olwazini lwakhe olubanzi lwe-chemistry yeqembu elikhulu, oluvuleke ensimini entsha.”
Konke kuncike kumakhemikhali ayisisekelo kanye nocwaningo, indlela eyenziwe yaba nokwenzeka yi-Open Klarman Fellowship, kusho uKong.
“Ngokuvamile ngingakwazi ukusebenzisa ukusabela elabhorethri noma ngihlale kukhompyutha ngilingisa i-molecule,” esho. “Sizama ukuthola isithombe esiphelele ngangokunokwenzeka somsebenzi wamakhemikhali.”