Okubukwayo kokuhluka okubili kwe-catalyst, kukhishwe ingxenye yegobolondo ukukhombisa ingaphakathi. I-white sphere imele igobolondo le-silica, izimbobo ziyizimbotshana. Ama-sphere aluhlaza ngokugqamile amele amasayithi e-catalytic, lawo angakwesokunxele mancane kakhulu kunalawo angakwesokudla. Izintambo ezinde ezibomvu zimelela amaketanga e-polymer, kanti izintambo ezimfishane ziyimikhiqizo ngemva kwe-catalysis. Wonke amayunithi ezinhlamvu amafushane afana ngosayizi, amele ukukhetha okungaguquguquki kukho konke ukuhlukahluka kwe-catalyst. Ukwengeza, kukhona amaketanga amancane kakhulu akhiqizwa izingosi ezincane ze-catalyst ngoba ukusabela kwenzeka ngokushesha okukhulu. Ikhredithi: Isithombe sihlonishwa yi-Argonne National Laboratory, Umnyango Wezamandla wase-US
Ubuchwepheshe bokukhushulwa kwamapulastiki buthuthukisiwe yi-catalyst esanda kwakhiwa yokudiliza amapulasitiki. Ithimba lososayensi eliholwa ososayensi be-Ames Laboratory bathola le I-catalyst yokuqala ye-inorganic ngo-2020 ukuze kwakhiwe amapulasitiki e-polyolefin abe ama-molecule angasetshenziswa ukwakha imikhiqizo ebaluleke kakhulu. Ithimba manje selithuthukise futhi laqinisekisa isu lokusheshisa uguquko ngaphandle kokudela imikhiqizo efiselekayo.
I-catalyst ekuqaleni yaklanywa u-Wenyu Huang, usosayensi e-Ames Laboratory. Iqukethe izinhlayiya zeplatinamu ezisekelwe kumongo we-silica oqinile futhi ozungezwe igobolondo le-silica elinezimbotshana ezifanayo ezinikeza ukufinyelela kumasayithi e-catalytic. Isamba senani leplatinamu elidingekayo lincane kakhulu, okubalulekile ngenxa yezindleko eziphakeme zeplatinamu nokutholakala okulinganiselwe. Ngesikhathi sokuhlolwa kokuqeda ukwakhiwa, amaketanga e-polymer amade angena ezimbotsheni futhi athintane nezindawo ze-catalytic, bese amaketango ehlukaniswa abe izingcezu ezinosayizi omncane ezingaseyona into yepulasitiki (bona isithombe esingenhla ukuze uthole imininingwane eyengeziwe).
Ngokuka-Aaron Sadow, usosayensi e-Ames Lab kanye nomqondisi we I-Institute for Cooperative Upcycling of Plastics (iCOUP), ithimba lenze izinhlobonhlobo ezintathu ze-catalyst. Ukwehluka ngakunye kwakunamacores anosayizi ofanayo namagobolondo anezimbotshana, kodwa amadayamitha ahlukahlukene ezinhlayiya zeplatinamu, ukusuka ku-1.7 kuye ku-2.9 kuya ku-5.0 nm.
Abacwaningi bacabanga ukuthi umehluko wesayizi wezinhlayiyana zeplatinamu uzothinta ubude bamaketanga omkhiqizo, ngakho-ke izinhlayiya ezinkulu zeplatinamu zingenza amaketanga amade futhi amancane angenza amaketanga amafushane. Nokho, ithimba lathola ukuthi ubude bamaketanga omkhiqizo babulingana kuwo womathathu ama-catalyst.
“Ezincwadini, ukukhetha kokusabela kwe-carbon-carbon bond cleavage kuvame ukuhluka ngosayizi we-platinum nanoparticles. Ngokubeka i-platinum ngaphansi kwezimbotshana, sibone into eyingqayizivele,” kusho uSadow.
Esikhundleni salokho, izinga lapho amaketanga ahlukaniswa khona abe ama-molecule amancane lalihlukile kuma-catalysts amathathu. Izinhlayiya ezinkulu zeplatinamu ziphendule ngeketango elide le-polymer kancane kancane kuyilapho ezincane zisabela ngokushesha okukhulu. Lesi silinganiselo esikhuphukile singase sibangelwe kumaphesenti aphezulu ezingosi zeplatinamu ezinqenqemeni nasekhoneni endaweni yama-nanoparticles amancane. Lezi zingosi zisebenza kakhulu ekuhlukaniseni iketango le-polymer kune-platinum etholakala ebusweni bezinhlayiya.
NgokukaSadow, imiphumela ibalulekile ngoba ibonisa ukuthi umsebenzi ungalungiswa ngokuzimela kusukela ekukhetheni kulokhu kusabela. "Manje, siyaqiniseka ukuthi singakwazi ukwenza i-catalyst esebenzayo engahlafuna i-polymer ngokushesha nakakhulu, kuyilapho sisebenzisa imingcele yesakhiwo se-catalyst ukudayela ubude beketanga lomkhiqizo othize," esho.
U-Huang wachaza ukuthi lolu hlobo lwe-molecule enkulu yokuphinda isebenze kuma-catalysts anezimbotshana ngokuvamile ayifundwa kabanzi. Ngakho-ke, ucwaningo lubalulekile ekuqondeni isayensi eyisisekelo kanye nendlela esebenza ngayo ekukhuphuleni amapulasitiki.
“Kumele siluqonde kahle lolu hlelo ngoba sisafunda izinto ezintsha nsuku zonke. Sibheka amanye amapharamitha esingawashuna ukuze sikhulise izinga lokukhiqiza futhi siguqule ukusatshalaliswa komkhiqizo,” kusho u-Huang. Ngakho-ke kunezinto eziningi ezintsha ohlwini lwethu ezilinde ukuthi sizithole.
Ireferensi: "Ama-Nanoparticles Alawulwa Usayizi Ashumekwe Ku-Architecture ye-Mesoporous Eholela Ekusebenzeni Ngokuphumelelayo Nokukhetha I-Hydrogenolysis ye-Polyolefins" ngu-Xun Wu, Akalanka Tennakoon, Ryan Yappert, Michaela Esveld, Magali S. Ferrandon, Ryan A. Hackler, Anne M. LaPointe, Andreas U-Heyden, uMassimiliano Delferro, u-Baron Peters, u-Aaron D. Sadow no-Wenyu Huang, 23 February 2022, I-Journal ye-American Chemical Society.
I-DOI: 10.1021/jacs.1c11694
Ucwaningo lwenziwe yi-Institute for Cooperative Upcycling of Plastics (iCOUP), eholwa yi-Ames Laboratory. I-iCOUP iyi-Energy Frontier Research Centre ehlanganisa ososayensi abavela e-Ames Laboratory, Argonne National Laboratory, UC Santa Barbara, University of South Carolina, Cornell University, Northwestern University, kanye neNyuvesi yase-Illinois Urbana-Champaign.
