Katalyz\u00e1tory jsou nepostradateln\u00fdmi sou\u010d\u00e1stmi modern\u00edch vozidel se spalovac\u00edmi motory a slou\u017e\u00ed jako prim\u00e1rn\u00ed technologie dodate\u010dn\u00e9 \u00fapravy v\u00fdfukov\u00fdch plyn\u016f pro zm\u00edrn\u011bn\u00ed \u0161kodliv\u00fdch emis\u00ed. Jejich kl\u00ed\u010dov\u00e1 role spo\u010d\u00edv\u00e1 v p\u0159em\u011bn\u011b toxick\u00fdch zne\u010di\u0161\u0165uj\u00edc\u00edch l\u00e1tek \u2013 jako jsou nesp\u00e1len\u00e9 uhlovod\u00edky (HC), oxid uhelnat\u00fd (CO) a oxidy dus\u00edku (NOx) \u2013 na m\u00e9n\u011b \u0161kodliv\u00e9 l\u00e1tky, jako je vodn\u00ed p\u00e1ra, oxid uhli\u010dit\u00fd a plynn\u00fd dus\u00edk. 10<\/a>Tato zpr\u00e1va se pono\u0159\u00ed do z\u00e1kladn\u00edch v\u011bdeck\u00fdch mechanism\u016f, kter\u00fdmi r\u016fzn\u00e9 slo\u017eky v\u00fdfukov\u00fdch plyn\u016f a provozn\u00ed podm\u00ednky sni\u017euj\u00ed v\u00fdkon a \u017eivotnost katalyz\u00e1tor\u016f. Prozkoum\u00e1me slo\u017eit\u00e9 chemick\u00e9 a fyzik\u00e1ln\u00ed procesy, kter\u00e9 vedou k deaktivaci nap\u0159\u00ed\u010d r\u016fzn\u00fdmi architekturami katalyz\u00e1tor\u016f, a poskytneme tak komplexn\u00ed pochopen\u00ed t\u011bchto komplexn\u00edch interakc\u00ed.<\/p>\n\n\n\n Katalyz\u00e1tory jsou sofistikovan\u00e9 chemick\u00e9 reaktory ur\u010den\u00e9 k usnadn\u011bn\u00ed specifick\u00fdch redoxn\u00edch reakc\u00ed. Jejich z\u00e1kladn\u00ed struktura se obvykle skl\u00e1d\u00e1 z keramick\u00e9ho (kordierit) nebo kovov\u00e9ho (fekralloy) vo\u0161tinov\u00e9ho monolitick\u00e9ho substr\u00e1tu, kter\u00fd poskytuje katalytick\u00e9mu n\u00e1t\u011bru vysok\u00fd geometrick\u00fd povrch. 37<\/a>Tato povrchov\u00e1 vrstva, por\u00e9zn\u00ed vrstva obvykle slo\u017een\u00e1 z oxid\u016f kov\u016f s vysok\u00fdm povrchem, jako je gama-oxid hlinit\u00fd (\u03b3-Al2O3), oxid k\u0159emi\u010dit\u00fd (SiO2), oxid titani\u010dit\u00fd (TiO2), oxid ceri\u010dit\u00fd (CeO2) a oxid zirkoni\u010dit\u00fd (ZrO2), je kl\u00ed\u010dov\u00e1 pro disperzi aktivn\u00edch katalytick\u00fdch materi\u00e1l\u016f. 40<\/a>Tlou\u0161\u0165ka n\u00e1t\u011bru se obvykle pohybuje v rozmez\u00ed 20\u201340 \u00b5m, co\u017e odpov\u00edd\u00e1 zat\u00ed\u017een\u00ed p\u0159ibli\u017en\u011b 100 g\/dm33 na substr\u00e1tech s hustotou 200 cpsi (bun\u011bk na \u010dtvere\u010dn\u00ed palec) a a\u017e 200 g\/dm33 na substr\u00e1tech s hustotou 400 cpsi. 57<\/a>Volba substr\u00e1tu a materi\u00e1lu washcoatu v\u00fdznamn\u011b ovliv\u0148uje tepelnou stabilitu, mechanickou pevnost a celkov\u00fd v\u00fdkon katalyz\u00e1toru. 37<\/a>.<\/p>\n\n\n\n V z\u00e1vislosti na typu motoru a emisn\u00edch c\u00edlech se pou\u017e\u00edvaj\u00ed r\u016fzn\u00e9 typy katalyz\u00e1tor\u016f:<\/p>\n\n\n\n Dvoucestn\u00e9 katalyz\u00e1tory, pou\u017e\u00edvan\u00e9 prim\u00e1rn\u011b u vzn\u011btov\u00fdch motor\u016f, se zam\u011b\u0159uj\u00ed na oxidaci uhlovod\u00edk\u016f a oxidu uhelnat\u00e9ho. 10<\/a>Obvykle obsahuj\u00ed platinu (Pt) a\/nebo palladium (Pd) jako aktivn\u00ed u\u0161lechtil\u00e9 kovy.<\/p>\n\n\n\n TWC jsou standardem pro benz\u00ednov\u00e9 motory a jsou navr\u017eeny tak, aby sou\u010dasn\u011b sni\u017eovaly emise t\u0159\u00ed hlavn\u00edch zne\u010di\u0161\u0165uj\u00edc\u00edch l\u00e1tek: oxid\u016f dus\u00edku (NOx), oxidu uhelnat\u00e9ho (CO) a nesp\u00e1len\u00fdch uhlovod\u00edk\u016f (HC). 4<\/a>T\u00e9to simult\u00e1nn\u00ed p\u0159em\u011bny je dosa\u017eeno jemnou rovnov\u00e1hou oxida\u010dn\u00edch a reduk\u010dn\u00edch reakc\u00ed, co\u017e vy\u017eaduje, aby motor pracoval v \u00fazk\u00e9m stechiometrick\u00e9m rozmez\u00ed pom\u011bru vzduchu a paliva (A\/F) (\u03bb = 1), obvykle mezi 14,6 a 14,8 u benz\u00ednu. 5<\/a>.<\/p>\n\n\n\n Aktivn\u00ed materi\u00e1ly v TWC jsou p\u0159ev\u00e1\u017en\u011b u\u0161lechtil\u00e9 kovy:<\/p>\n\n\n\n Prim\u00e1rn\u00ed chemick\u00e9 reakce prob\u00edhaj\u00edc\u00ed v TWC jsou:<\/p>\n\n\n\n Oxidy obecn\u00fdch kov\u016f, zejm\u00e9na oxid ceri\u010dit\u00fd (CeO2), \u010dasto ve form\u011b sm\u011bsn\u00e9ho oxidu CeO2-ZrO2, hraj\u00ed z\u00e1sadn\u00ed roli jako slo\u017eky pro ukl\u00e1d\u00e1n\u00ed kysl\u00edku (OSC). 1<\/a>Tato kapacita pro ukl\u00e1d\u00e1n\u00ed kysl\u00edku pom\u00e1h\u00e1 tlumit kol\u00eds\u00e1n\u00ed pom\u011bru A\/F, prodlu\u017euje \u201eokno katalyz\u00e1toru\u201c a udr\u017euje vysokou \u00fa\u010dinnost p\u0159em\u011bny i b\u011bhem p\u0159echodn\u00e9ho provozu motoru. 5<\/a>Nap\u0159\u00edklad spole\u010dnost Monolithos Catalysts & Recycling Ltd. vyvinula PROMETHEUS, katalyz\u00e1tor TWC obsahuj\u00edc\u00ed nano\u010d\u00e1stice Cu, Pd a Rh nanesen\u00e9 na sm\u011bsn\u00fd oxid CeO2-ZrO2 s vysokou OSC, co\u017e dokazuje d\u016fle\u017eitost t\u011bchto sm\u011bsn\u00fdch oxid\u016f. 1<\/a>.<\/p>\n\n\n\n Vzn\u011btov\u00e9 motory pracuj\u00ed s chud\u00fdmi sm\u011bsmi paliva (s p\u0159ebytkem kysl\u00edku), co\u017e zt\u011b\u017euje sni\u017eov\u00e1n\u00ed emis\u00ed NOx u tradi\u010dn\u00edch motor\u016f s tepeln\u00fdm \u010derpadlem. Pou\u017e\u00edvaj\u00ed se specializovan\u00e9 syst\u00e9my:<\/p>\n\n\n\n Celkovou \u00fa\u010dinnost katalyz\u00e1tor\u016f ovliv\u0148uj\u00ed faktory, jako je hustota bun\u011bk, tlou\u0161\u0165ka st\u011bny a geometrick\u00fd povrch substr\u00e1tu. 38<\/a>Vy\u0161\u0161\u00ed hustota bun\u011bk obecn\u011b zlep\u0161uje v\u00fdkon zv\u011bt\u0161en\u00edm plochy pro p\u0159enos hmoty, ale tak\u00e9 zvy\u0161uje tlakovou ztr\u00e1tu. 38<\/a>.<\/p>\n\n\n\n V\u00fdfukov\u00e9 plyny jsou slo\u017eitou sm\u011bs\u00ed slo\u017eek, z nich\u017e n\u011bkter\u00e9 jsou ur\u010deny k p\u0159em\u011bn\u011b katalyz\u00e1torem (reaktanty), zat\u00edmco jin\u00e9 mohou v\u00e1\u017en\u011b sn\u00ed\u017eit jeho v\u00fdkon (jedy) nebo v n\u011bkter\u00fdch p\u0159\u00edpadech zv\u00fd\u0161it jeho aktivitu (promotory).<\/p>\n\n\n\n Prim\u00e1rn\u00edmi c\u00edlov\u00fdmi zne\u010di\u0161\u0165uj\u00edc\u00edmi l\u00e1tkami pro katalytickou konverzi jsou:<\/p>\n\n\n\n Otrava katalyz\u00e1toru je deaktivace katalyz\u00e1toru chemickou cestou, odli\u0161n\u00e1 od tepeln\u00e9 degradace nebo fyzick\u00e9ho po\u0161kozen\u00ed. 6<\/a>Jedy se obvykle chemicky v\u00e1\u017eou na aktivn\u00ed m\u00edsta katalyz\u00e1toru nebo s nimi reaguj\u00ed, \u010d\u00edm\u017e sni\u017euj\u00ed jejich dostupnost a zv\u011bt\u0161uj\u00ed difuzn\u00ed vzd\u00e1lenost molekul reaktantu. 6<\/a>To vede ke zv\u00fd\u0161en\u00ed teploty zhasnut\u00ed sv\u011btla a sn\u00ed\u017een\u00ed maxim\u00e1ln\u00ed \u00fa\u010dinnosti konverze. 7<\/a>Otrava m\u016f\u017ee b\u00fdt vratn\u00e1 nebo nevratn\u00e1, p\u0159i\u010dem\u017e vratnost se \u010dasto zvy\u0161uje p\u0159i vy\u0161\u0161\u00edch teplot\u00e1ch v reduk\u010dn\u00edm prost\u0159ed\u00ed. 8<\/a>.<\/p>\n\n\n\n Mezi kl\u00ed\u010dov\u00e9 katalytick\u00e9 jedy pat\u0159\u00ed:<\/p>\n\n\n\n N\u011bkter\u00e9 slo\u017eky nebo p\u0159\u00edsady mohou zv\u00fd\u0161it aktivitu nebo trvanlivost katalyz\u00e1toru:<\/p>\n\n\n\n Chemick\u00e1 otrava je kritickou degrada\u010dn\u00ed cestou, kter\u00e1 vede k nevratn\u00e9 nebo semi-reverzibiln\u00ed deaktivaci aktivn\u00edch m\u00edst katalyz\u00e1toru. Tato \u010d\u00e1st podrobn\u011b popisuje mechanismy kl\u00ed\u010dov\u00fdch jed\u016f na atom\u00e1rn\u00ed \u00farovni.<\/p>\n\n\n\n Slou\u010deniny s\u00edry, p\u0159edev\u0161\u00edm H2S a SO2, jsou siln\u00fdmi katalytick\u00fdmi jedy. Mechanismus zahrnuje silnou adsorpci a reakci slou\u010denin s\u00edry s aktivn\u00edmi kovov\u00fdmi m\u00edsty, co\u017e je \u00fa\u010dinn\u011b blokuje a br\u00e1n\u00ed molekul\u00e1m reaktant\u016f v p\u0159\u00edstupu na katalytick\u00fd povrch. 17<\/a>.<\/p>\n\n\n\n Fosfor, prim\u00e1rn\u011b z aditiv do mazac\u00edch olej\u016f, jako je ZDDP, deaktivuje katalyz\u00e1tory vytvo\u0159en\u00edm fyzick\u00e9 bari\u00e9ry a chemickou interakc\u00ed s kryc\u00edm n\u00e1t\u011brem.<\/p>\n\n\n\n Olovo, historicky poch\u00e1zej\u00edc\u00ed z olovnat\u00e9ho benzinu, je vysoce \u0161kodliv\u00fd a do zna\u010dn\u00e9 m\u00edry nevratn\u00fd katalytick\u00fd jed.<\/p>\n\n\n\n Stru\u010dn\u011b \u0159e\u010deno, mechanismy chemick\u00e9 otravy zahrnuj\u00ed tvorbu siln\u00fdch chemick\u00fdch vazeb nebo fyzik\u00e1ln\u00edch bari\u00e9r na aktivn\u00edch m\u00edstech a kryc\u00ed vrstv\u011b katalyz\u00e1toru, co\u017e vede k trval\u00e9mu sn\u00ed\u017een\u00ed katalytick\u00e9 aktivity a \u00fa\u010dinnosti konverze. Reverzibilita otravy siln\u011b z\u00e1vis\u00ed na konkr\u00e9tn\u00edm jedu, jeho chemick\u00e9 form\u011b a provozn\u00edch podm\u00ednk\u00e1ch.<\/p>\n\n\n\n Thermal degradation, particularly sintering, is a major cause of catalytic converter deactivation, especially at temperatures exceeding 500\u00b0C [L.5.3]. This process involves the irreversible loss of active surface area due to the agglomeration of noble metal particles and the structural collapse of the washcoat.<\/p>\n\n\n\n Slinov\u00e1n\u00ed ozna\u010duje r\u016fst \u010d\u00e1stic u\u0161lechtil\u00fdch kov\u016f (Pt, Pd, Rh) p\u0159i zv\u00fd\u0161en\u00fdch teplot\u00e1ch, co\u017e vede ke sn\u00ed\u017een\u00ed celkov\u00e9 aktivn\u00ed povrchov\u00e9 plochy dostupn\u00e9 pro katalytick\u00e9 reakce. 22<\/a>.<\/p>\n\n\n\n Samotn\u00fd n\u00e1t\u011br m\u016f\u017ee podl\u00e9hat tepeln\u00e9 degradaci, co\u017e vede ke zmen\u0161en\u00ed jeho velk\u00e9ho povrchu a objemu p\u00f3r\u016f.<\/p>\n\n\n\n Vz\u00e1jemn\u00e9 p\u016fsoben\u00ed mezi slinov\u00e1n\u00edm u\u0161lechtil\u00fdch kov\u016f a degradac\u00ed kryc\u00edho povlaku je slo\u017eit\u00e9. Siln\u00e9 interakce mezi kovem a nosi\u010dem, jako jsou vazby Pt-O-Ce, jsou nezbytn\u00e9 pro stabilizaci u\u0161lechtil\u00fdch kov\u016f a prevenci jejich aglomerace, \u010d\u00edm\u017e se zvy\u0161uje tepeln\u00e1 stabilita katalyz\u00e1toru. 24<\/a>P\u0159edb\u011b\u017en\u00e1 kalcinace nosn\u00fdch materi\u00e1l\u016f m\u016f\u017ee tak\u00e9 ovlivnit disperzi u\u0161lechtil\u00fdch kov\u016f a odolnost v\u016f\u010di slinov\u00e1n\u00ed. 26<\/a>.<\/p>\n\n\n\n Krom\u011b chemick\u00e9 a tepeln\u00e9 degradace jsou katalyz\u00e1tory tak\u00e9 n\u00e1chyln\u00e9 k fyzick\u00e9mu po\u0161kozen\u00ed v d\u016fsledku p\u016fsoben\u00ed slo\u017eek v\u00fdfukov\u00fdch plyn\u016f a mechanick\u00e9ho nam\u00e1h\u00e1n\u00ed.<\/p>\n\n\n\n Saze, zejm\u00e9na ze spalov\u00e1n\u00ed nafty, mohou fyzicky blokovat aktivn\u00ed m\u00edsta katalyz\u00e1toru, co\u017e je jev zn\u00e1m\u00fd jako maskov\u00e1n\u00ed 27<\/a>.<\/p>\n\n\n\n Neust\u00e1l\u00fd proud hork\u00fdch v\u00fdfukov\u00fdch plyn\u016f, zejm\u00e9na t\u011bch, kter\u00e9 obsahuj\u00ed pevn\u00e9 \u010d\u00e1stice, m\u016f\u017ee v\u00e9st k fyzick\u00e9 erozi laku.<\/p>\n\n\n\n Katalyz\u00e1tory jsou b\u011bhem provozu vozidla vystaveny zna\u010dn\u00e9mu mechanick\u00e9mu nam\u00e1h\u00e1n\u00ed, kter\u00e9 m\u016f\u017ee v\u00e9st k po\u0161kozen\u00ed konstrukce.<\/p>\n\n\n\n Tyto mechanismy fyzik\u00e1ln\u00ed degradace p\u0159\u00edmo sni\u017euj\u00ed efektivn\u00ed katalytick\u00fd povrch, br\u00e1n\u00ed p\u0159enosu hmoty zne\u010di\u0161\u0165uj\u00edc\u00edch l\u00e1tek a mohou v\u00e9st ke katastrofick\u00e9mu selh\u00e1n\u00ed konvertoru.<\/p>\n\n\n\n Provozn\u00ed podm\u00ednky motoru hraj\u00ed kl\u00ed\u010dovou roli v urychlen\u00ed nebo zm\u00edrn\u011bn\u00ed rychlosti chemick\u00e9 otravy, tepeln\u00e9 degradace a fyzick\u00e9ho po\u0161kozen\u00ed.<\/p>\n\n\n\n U t\u0159\u00edcestn\u00fdch katalyz\u00e1tor\u016f je pro optim\u00e1ln\u00ed v\u00fdkon z\u00e1sadn\u00ed udr\u017eov\u00e1n\u00ed p\u0159esn\u00e9ho stechiometrick\u00e9ho pom\u011bru vzduch-palivo (A\/F) (\u03bb=1). 4<\/a>Odchylky od tohoto \u00fazk\u00e9ho \u201eokna katalyz\u00e1toru\u201c mohou v\u00e9st k ne\u00fapln\u00e9 p\u0159em\u011bn\u011b zne\u010di\u0161\u0165uj\u00edc\u00edch l\u00e1tek a v n\u011bkter\u00fdch p\u0159\u00edpadech p\u0159isp\u00edvat k degradaci katalyz\u00e1toru. Nap\u0159\u00edklad u chud\u00fdch sm\u011bs\u00ed maj\u00ed v\u00fdfukov\u00e9 plyny vysok\u00fd obsah NOx a n\u00edzk\u00fd obsah CO\/HC, zat\u00edmco bohat\u00e9 sm\u011bsi maj\u00ed vysok\u00fd obsah CO\/HC a n\u00edzk\u00fd obsah NOx. 5<\/a>P\u0159esn\u00e1 regulace pom\u011bru A\/F, \u010dasto dosahovan\u00e1 zp\u011btnou vazbou z lambda sondy, je nezbytn\u00e1. 5<\/a>.<\/p>\n\n\n\n Vynech\u00e1v\u00e1n\u00ed zapalov\u00e1n\u00ed motoru, kdy sm\u011bs vzduchu a paliva v jednom nebo v\u00edce v\u00e1lc\u00edch spr\u00e1vn\u011b nespaluje, je velmi \u0161kodliv\u00e9 pro katalyz\u00e1tory. 52<\/a>.<\/p>\n\n\n\n Zat\u00edmco kr\u00e1tk\u00e9 v\u00fdkyvy jsou zvl\u00e1d\u00e1ny kapacitou skladov\u00e1n\u00ed kysl\u00edku, dlouhodob\u00fd provoz mimo stechiometrick\u00e9 okno m\u016f\u017ee degradaci urychlit.<\/p>\n\n\n\n The operating temperature of the catalyst is critical. While high temperatures accelerate sintering, a certain temperature is necessary for the catalytic reactions to occur efficiently. For instance, in biomass pyrolysis vapor upgrading, increasing catalyst temperature can counteract deactivation, but the rate of increase needs optimization [L.5.8]. An optimal operating temperature range exists for catalysts, balancing conversion efficiency and minimizing coke formation [L.5.11].<\/p>\n\n\n\n Degradace katalyz\u00e1toru se projevuje v kvantifikovateln\u00fdch v\u00fdkonnostn\u00edch ukazatel\u00edch, kter\u00e9 p\u0159\u00edmo ovliv\u0148uj\u00ed shodu s emisn\u00edmi p\u0159edpisy vozidel a celkovou funk\u010dnost.<\/p>\n\n\n\n Nejp\u0159\u00edm\u011bj\u0161\u00edm d\u016fsledkem degradace katalyz\u00e1toru je sn\u00ed\u017een\u00ed jeho schopnosti p\u0159em\u011b\u0148ovat \u0161kodliv\u00e9 zne\u010di\u0161\u0165uj\u00edc\u00ed l\u00e1tky na ne\u0161kodn\u00e9 l\u00e1tky.<\/p>\n\n\n\n Teplota zhasnut\u00ed (T50 nebo T90, co\u017e p\u0159edstavuje teplotu, p\u0159i kter\u00e9 se p\u0159em\u011bn\u00ed 50 %, respektive 90 % zne\u010di\u0161\u0165uj\u00edc\u00ed l\u00e1tky) je kritick\u00fdm ukazatelem v\u00fdkonu katalyz\u00e1toru.<\/p>\n\n\n\n D\u016fsledky degradace p\u0159\u00edmo ovliv\u0148uj\u00ed schopnost vozidla spl\u0148ovat p\u0159\u00edsn\u00e9 emisn\u00ed p\u0159edpisy.<\/p>\n\n\n\n Degradace katalyz\u00e1toru v podstat\u011b ohro\u017euje samotn\u00fd \u00fa\u010del katalyz\u00e1toru, co\u017e vede k po\u0161kozen\u00ed \u017eivotn\u00edho prost\u0159ed\u00ed a provozn\u00edm probl\u00e9m\u016fm s vozidlem.<\/p>\n\n\n\n \u0158e\u0161en\u00ed degradace katalyz\u00e1tor\u016f je v automobilov\u00e9m in\u017een\u00fdrstv\u00ed neust\u00e1lou v\u00fdzvou. Sou\u010dasn\u00e9 i nov\u011b vznikaj\u00edc\u00ed strategie se zam\u011b\u0159uj\u00ed na zv\u00fd\u0161en\u00ed trvanlivosti, zlep\u0161en\u00ed slo\u017een\u00ed katalyz\u00e1tor\u016f a optimalizaci \u0159\u00edzen\u00ed motoru.<\/p>\n\n\n\n V\u00fdznamn\u00fd v\u00fdzkum a v\u00fdvoj se zam\u011b\u0159uje na vytvo\u0159en\u00ed robustn\u011bj\u0161\u00edch a \u00fa\u010dinn\u011bj\u0161\u00edch katalyz\u00e1tor\u016f.<\/p>\n\n\n\n2. Architektura a principy fungov\u00e1n\u00ed katalyz\u00e1tor\u016f<\/h2>\n\n\n\n
2.1. Dvoucestn\u00e9 katalyz\u00e1tory<\/h3>\n\n\n\n
2.2. Trojcestn\u00e9 katalyz\u00e1tory (TWC)<\/h3>\n\n\n\n
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2.3. Katalyz\u00e1tory NOx pro naftu\/chudou sm\u011bs<\/h3>\n\n\n\n
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3. Slo\u017eky v\u00fdfukov\u00fdch plyn\u016f: reaktanty, jedy a promotory<\/h2>\n\n\n\n
3.1. Reaktanty<\/h3>\n\n\n\n
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3.2. Jedy<\/h3>\n\n\n\n
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3.3. Po\u0159adatel\u00e9<\/h3>\n\n\n\n
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4. Chemick\u00e1 otrava: Mechanismy deaktivace aktivn\u00edho m\u00edsta<\/h2>\n\n\n\n
4.1. Otrava s\u00edrou<\/h3>\n\n\n\n
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4.2. Otrava fosforem<\/h3>\n\n\n\n
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4.3. Otrava olovem<\/h3>\n\n\n\n
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4.4. Otrava k\u0159em\u00edkem a zinkem<\/h3>\n\n\n\n
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5. Tepeln\u00e1 degradace (sp\u00e9k\u00e1n\u00ed): Vliv vysok\u00fdch teplot na strukturu katalyz\u00e1toru<\/h2>\n\n\n\n
5.1. Slinov\u00e1n\u00ed u\u0161lechtil\u00fdch kov\u016f<\/h3>\n\n\n\n
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5.2. Zhroucen\u00ed konstrukce omyvac\u00edho n\u00e1t\u011bru<\/h3>\n\n\n\n
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6. Fyzik\u00e1ln\u00ed degradace: eroze, maskov\u00e1n\u00ed a mechanick\u00e9 po\u0161kozen\u00ed<\/h2>\n\n\n\n
6.1. Maskov\u00e1n\u00ed saz\u00ed<\/h3>\n\n\n\n
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6.2. Eroze om\u00fdvac\u00edho n\u00e1t\u011bru<\/h3>\n\n\n\n
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6.3. Mechanick\u00e9 po\u0161kozen\u00ed<\/h3>\n\n\n\n
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7. Vliv provozn\u00edch podm\u00ednek na rychlost degradace<\/h2>\n\n\n\n
7.1. Norm\u00e1ln\u00ed stechiometrick\u00fd provoz<\/h3>\n\n\n\n
7.2. Vynech\u00e1v\u00e1n\u00ed zapalov\u00e1n\u00ed<\/h3>\n\n\n\n
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7.3. Dlouhodob\u00e9 v\u00fdkyvy mezi bohatou a chudou stravou<\/h3>\n\n\n\n
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7.4. Studen\u00e9 starty a p\u0159echodn\u00e9 jevy<\/h3>\n\n\n\n
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7.5. \u0158\u00edzen\u00ed teploty<\/h3>\n\n\n\n
8. D\u016fsledky degradace: Ukazatele v\u00fdkonu a dopad na emise<\/h2>\n\n\n\n
8.1. Sn\u00ed\u017een\u00e1 \u00fa\u010dinnost konverze<\/h3>\n\n\n\n
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8.2. Zv\u00fd\u0161en\u00e1 teplota p\u0159i zhasnut\u00ed sv\u011btla (T50, T90)<\/h3>\n\n\n\n
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8.3. Dopad emis\u00ed a dodr\u017eov\u00e1n\u00ed p\u0159edpis\u016f<\/h3>\n\n\n\n
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9. Strategie zm\u00edr\u0148ov\u00e1n\u00ed a budouc\u00ed katalytick\u00e9 technologie<\/h2>\n\n\n\n
9.1. Kvalita paliva a maziv<\/h3>\n\n\n\n
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9.2. \u0158\u00edzen\u00ed a \u00fadr\u017eba motoru<\/h3>\n\n\n\n
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9.3. Pokro\u010dil\u00e9 katalytick\u00e9 formulace a materi\u00e1ly pro washcoat<\/h4>\n\n\n\n
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