Vim qhov kev loj hlob sai ntawm kev lag luam, cov tshuaj tiv thaiv catalytic tau dhau los ua ntau dua hauv kev xav tau hauv kev tsim tshuaj, tshuab engineering, thiab metallurgy. Ua tsaug rau kev siv cov catalysts, nws muaj peev xwm tig cov khoom siv qis rau hauv cov khoom muaj txiaj ntsig.
Qhov tseem ceeb
Catalytic cov tshuaj tiv thaiv yog qhov txawv los ntawm ntau hom tshuaj siv. Nyob rau hauv cov organic synthesis, lawv pab txhawb rau ib tug tseem ceeb acceleration ntawm dehydrogenation, hydrogenation, hydration, oxidation, thiab polymerization. Cov catalyst tuaj yeem suav hais tias yog "tus kws tshaj lij lub pob zeb" uas hloov cov ntaub ntawv raw rau hauv cov khoom tiav: fibers, tshuaj, tshuaj, chiv, roj, plastics.
Catalytic cov tshuaj tiv thaiv ua rau nws ua tau kom tau txais ntau yam khoom, yam tsis muaj lub neej ib txwm muaj thiab kev ua haujlwm ntawm tib neeg ua tsis tau.
Catalysis tso cai rau koj kom ceev cov txheej txheem hauvtxhiab thiab ntau lab lub sij hawm, uas yog vim li cas tam sim no nws yog siv nyob rau hauv 91% ntawm ntau yam tshuaj industries.
Ntiaj teb qhov tseeb
Ntau cov txheej txheem kev lag luam niaj hnub no, xws li kev sib txuas ntawm sulfuric acid, tsuas yog tuaj yeem nqa tawm siv lub catalyst. Ntau hom catalytic agents ua kom muaj kev tsim cov roj cav rau kev lag luam tsheb. Nyob rau xyoo 1900, thawj zaug ntawm kev lag luam nplai, catalytic synthesis ntawm margarine los ntawm zaub raw cov ntaub ntawv (los ntawm hydrogenation) tau ua.
Txij li xyoo 1920, lub tshuab tau tsim los rau cov tshuaj tiv thaiv catalytic hauv kev tsim cov fibers thiab yas. Qhov xwm txheej tseem ceeb yog kev tsim cov tshuaj esters, olefins, carboxylic acids, nrog rau lwm yam khoom siv pib rau kev tsim cov khoom siv polymer.
Roj refining
Txij li nruab nrab ntawm ib puas xyoo dhau los, cov tshuaj tiv thaiv catalytic tau siv rau hauv cov roj refining. Kev ua tiav ntawm cov peev txheej ntuj tsim nyog no suav nrog ntau cov txheej txheem catalytic ib zaug:
- reforming;
- ncig;
- Yhydrosulfonation;
- polymerization;
- hydrocracking;
- alkylation.
Txij li thaum xaus ntawm lub xyoo pua xeem, nws muaj peev xwm tsim tau lub catalytic converter kom txo cov pa tawm mus rau hauv qhov chaw.
Ntau qhov khoom plig Nobel tau txais txiaj ntsig rau kev ua haujlwm hauv catalysis thiab lwm yam.
Practical relevance
Cov tshuaj tiv thaiv catalytic yog ib txheej txheem uas siv cov accelerators (catalysts). Txhawm rau ntsuas qhov tseem ceeb ntawm cov kev sib cuam tshuam zoo li no, ib tus tuaj yeem hais ua piv txwv txog kev cuam tshuam nrog nitrogen thiab nws cov tebchaw. Txij li cov nyiaj no muaj tsawg heev nyob rau hauv qhov xwm txheej, kev tsim cov khoom noj protein tsis siv cov khoom siv ammonia yog teeb meem heev. Qhov teeb meem tau daws nrog kev txhim kho ntawm Haber-Bosch cov txheej txheem catalytic. Kev siv cov catalysts tau nthuav dav tas li, uas ua rau nws muaj peev xwm ua kom muaj txiaj ntsig ntawm ntau cov thev naus laus zis.
Ammonia ntau lawm
Cia peb xav txog qee qhov kev cuam tshuam catalytic. Piv txwv los ntawm inorganic chemistry yog muab los ntawm cov kev lag luam feem ntau. Lub synthesis ntawm ammonia yog exothermic, reversible cov tshuaj tiv thaiv, uas yog yus muaj los ntawm ib tug txo nyob rau hauv lub ntim ntawm cov gaseous tshuaj. Cov txheej txheem yuav siv sij hawm qhov chaw ntawm lub catalyst, uas yog ntxeem tau hlau nrog ntxiv ntawm aluminium oxide, calcium, potassium, silicon. Xws li lub catalyst yog nquag thiab ruaj khov nyob rau hauv qhov kub thiab txias ntawm 650-830K.
Irreversibly xa nws cov sulfur compounds, tshwj xeeb carbon monoxide (CO). Ob peb xyoos dhau los, ua tsaug rau kev qhia txog cov thev naus laus zis tshiab, lub siab tau txo qis. Piv txwv li, ib lub converter tau tsim uas tso cai rau koj txo qhov ntsuas qhov siab mus rau 8106 - 15106 Pa.
Kev hloov pauv ntawm lub hauv ntej Circuit Court tau txo qis qhov tshwm sim ntawm kev nrhiav cov tshuaj lom catalytic hauv nws - cov tshuaj sulfur,tshuaj chlorine. Cov kev xav tau rau cov catalyst kuj tau nce ntau. Yog tias ua ntej nws tau tsim los ntawm melting hlau oxides (scale), ntxiv magnesium thiab calcium oxides, tam sim no cob alt oxide plays lub luag hauj lwm ntawm ib tug tshiab activator.
Oxidation ntawm ammonia
Dab tsi yog cov yam ntxwv ntawm cov tshuaj tiv thaiv catalytic thiab tsis yog catalytic? Piv txwv ntawm cov txheej txheem uas nyob ntawm qhov sib ntxiv ntawm qee yam tshuaj tuaj yeem txiav txim siab raws li oxidation ntawm ammonia:
4NH3+ 5O2=4NO+ 6H2O.
txheej txheem no tuaj yeem ua tau ntawm qhov kub txog li 800 ° C, nrog rau kev xaiv catalyst. Txhawm rau ua kom nrawm nrawm, platinum thiab nws cov alloys nrog manganese, hlau, chromium, thiab cob alt yog siv. Tam sim no, lub ntsiab kev lag luam catalyst yog sib xyaw ntawm platinum nrog rhodium thiab palladium. Txoj hauv kev no ua rau nws tuaj yeem txo tus nqi ntawm cov txheej txheem.
Kwv txhiaj tawm tshiab
Xav txog qhov sib npaug ntawm cov tshuaj tiv thaiv catalytic, ib tus tsis tuaj yeem tsis quav ntsej cov tshuaj tiv thaiv ntawm kev tau txais cov pa oxygen thiab hydrogen los ntawm dej electrolysis. Cov txheej txheem suav nrog cov nqi hluav taws xob tseem ceeb, yog li nws tau siv ntau zaus ntawm kev lag luam.
Hlau platinum nrog qhov loj me ntawm li 5-10 nm (nanoclusters) ua raws li kev pom zoo rau cov txheej txheem zoo li no. Cov kev taw qhia ntawm xws li ib tug tshuaj accelerates lub decomposition ntawm dej los ntawm 20-30 feem pua. Lwm cov txiaj ntsig suav nrog kev ruaj ntseg ntawm platinum carbon monoxide catalyst.
In 2010ib pab neeg ntawm Asmeskas cov kws tshawb fawb tau txais cov khoom siv pheej yig uas txo cov kev siv hluav taws xob rau dej electrolysis. Lawv tau los ua ib qho kev sib xyaw ntawm npib tsib xee thiab boron, tus nqi qis dua platinum. Cov boron-nickel catalyst tau txais txiaj ntsig hauv kev tsim cov hydrogen industrial.
YSynthesis of txhuas iodide
Tau cov ntsev no los ntawm kev ua cov hmoov txhuas nrog iodine. Ib tee dej yog txaus los ua ib tug catalyst los pib tshuaj.
Ua ntej, aluminium oxide zaj duab xis ua haujlwm ua kom nrawm ntawm cov txheej txheem. Iodine, yaj nyob rau hauv dej, tsim ib tug sib tov ntawm hydroiodic thiab iodic acids. Cov kua qaub, tig mus, dissolves aluminium oxide zaj duab xis, ua lub catalyst rau cov txheej txheem tshuaj.
Summarize
Txhua xyoo, qhov ntsuas ntawm kev siv cov txheej txheem catalytic hauv ntau qhov chaw ntawm kev lag luam niaj hnub no nce ntxiv. Catalysts yog nyob rau hauv kev thov uas tso cai rau koj mus rau neutralize cov khoom uas muaj kev phom sij rau ib puag ncig. Lub luag hauj lwm ntawm cov tebchaw tsim nyog rau kev tsim cov hluavtaws hydrocarbons los ntawm cov thee thiab roj kuj tseem loj tuaj. Cov thev naus laus zis tshiab pab txo cov nqi hluav taws xob hauv kev tsim khoom ntawm ntau yam khoom.
Ua tsaug rau catalysis, nws muaj peev xwm tau txais cov khoom sib xyaw polymer, cov khoom muaj txiaj ntsig zoo, ua kom cov thev naus laus zis hloov pauv roj mus rau hauv hluav taws xob hluav taws xob, tsim cov khoom tsim nyog rautib neeg lub neej thiab kev ua ub no.
