Chinhu chine hunyanzvi chinoshandura gasi repropane kuita mahydrocarboni anorema chakagadzirwa neSaudi Arabia King Abdullah University of Science and Technology. (KAUST) vatsvakurudzi. Iyo inomhanyisa zvakanyanya kuita kwemakemikari inozivikanwa se alkane metathesis, inogona kushandiswa kugadzira mafuta emvura.

Iyo catalyst inorongazve propane, iyo ine matatu maatomu ekabhoni, mune mamwe mamorekuru, akadai sebutane (ine makabhoni mana), pentane (ine makabhoni mashanu) uye ethane (ine maviri kabhoni). "Chinangwa chedu ndechekushandura yakaderera molecular uremu alkanes anokosha dizeli-range alkanes," akadaro Manoja Samantaray kubva KAUST Catalysis Center.

Pamwoyo wechigadziriso pane maumbirwo emasimbi maviri, titanium uye tungsten, ayo akasungirirwa kune silica pamusoro kuburikidza nemaatomu eokisijeni. Nzira yakashandiswa yaiva catalysis by design. Zvidzidzo zvekare zvakaratidza kuti monometallic catalysts vaiita mabasa maviri: alkane kune olefin uyezve olefin metathesis. Titanium yakasarudzwa nekuda kwekugona kwayo kumisa CH chisungo cheparafini kuti ichishandure kuva olefins, uye tungsten yakasarudzwa nekuda kwekuita kwayo kwepamusoro kweolefin metathesis.

Kugadzira iyo catalyst, timu yakapisa silica kuti ibvise mvura yakawanda sezvinobvira uye yobva yawedzera hexamethyl tungsten uye tetraneopentyl titanium, ichigadzira hupfu-yero. Vatsvakurudzi vakaongorora catalyst vachishandisa nuclear magnetic resonance (NMR) spectroscopy kuratidza kuti tungsten uye titanium maatomu anorara padhuze nepadhuze panzvimbo yesilica, pamwe padyo se ≈0.5 nanometres.

Vatsvakurudzi, vakatungamirirwa neMutungamiri wepakati Jean-Marie Basset, vakabva vaedza iyo catalyst nekuipisa kusvika ku150 ° C ne propane kwemazuva matatu. Mushure mekugadzirisa mamiriro ekuita - semuenzaniso, nekubvumira kuti propane irambe ichiyerera pamusoro peiyo catalyst - vakawana kuti zvigadzirwa zvikuru zveiyo reaction yaive ethane uye butane uye kuti maviri ega ega etungsten nemaatomu etitanium aigona kukonzeresa avhareji ye10,000 ma cycles zvisati zvaitika. kurasikirwa nebasa ravo. Iyi "nhamba yekuchinja" ndiyo yakanyanya kutaurwa nezve propane metathesis reaction.

Uku kubudirira kwecatalysis nekugadzira, vaongorori vanoti, imhaka yeinotarisirwa kushanda pamwe pakati pesimbi mbiri. Chekutanga, atomu yetitanium inobvisa maatomu ehydrogen kubva mupropane kuita propene uyezve atomu remuvakidzani retungsten rinopwanya propene yakavhurika pacarbon-carbon double bond, ichigadzira zvimedu zvinogona kubatanidzwazve kuita mamwe mahydrocarbon. Vatsvakurudzi vakawanawo kuti catalyst powders ine tungsten chete kana titanium yakaita zvakashata zvikuru; kunyange apo pfumbu mbiri idzi dzakasanganiswa pamwe chete, kuita kwavo kwakanga kusingaenderani ne cooperative catalyst.

Chikwata chinotarisira kugadzira chinotova nani chine nhamba yepamusoro yekuchinja, uye hupenyu hurefu. "Tinotenda kuti munguva pfupi iri kutevera, indasitiri inogona kutora nzira yedu yekugadzira dhiziri-renji alkanes uye zvakanyanya kuita catalysis nedhizaini," akadaro Samantaray.