Feihu Liu,Zhong Wang,Da Wang,Dan Chen,Fushan Chen,Xuebing Li
The CeO2ordinary amorphous, nanopolyhedrons, nanorods, and nanocubes were prefabricated by the hydrothermal method, and employed as carriers of Fe/W–CeO2catalysts to selectively catalyze the reduction of NO with ammonia. Characterization results indicated that the morphology of CeO2support originated from selectively exposing different crystal surfaces, which has a significant effect on oxygen vacancies, acid sites and the dispersion of Fe2O3. The CeO2nanopolyhedrons catalyst (Fe/W–CeO2–P) showed most oxygen vacancies, the largest the quantity of acid sites, the largest BET (Brunauer-Emmett-Teller) surface area and the best dispersion of Fe2O3, which was associated with predominately exposing CeO2(111) planes. Consequently, the Fe/W–CeO2–P catalyst has the highest NO conversion rate in the temperature range of 100–325 °C among the ordinary amorphous, nanorods, and nanocubes Fe/W–CeO2catalysts.Keywords:morphology;Fe/W–CeO2;nanopolyhedra;CeO2(111) planes
Lignin-based guaiacol and its derivatives can be hydrogenated to synthesize 2-methoxycyclohexanols (2-MCHs), widely used in the pharmaceutical industry, while the efficient catalytic conversion of guaiacols into 2-MCHs is challenging due to the interference of the side reaction of CAr-OCH3 bond cleavage. In this work, highly selective hydrogenation of various guaiacyl lignin-derived phenols to 2-MCHs (yields of 86%-97%) was realized over a single-atom Ru-based catalyst (Ru1/o-CeO2-ov) that preferentially exposes the CeO2(111) plane and has abundant oxygen vacancies. Control experiments and mechanism studies expounded that Ru-O-Ce is the active site for hydrogenation of aromatic ring in guaiacols, and the exposed (111) plane and abundant oxygen vacancies of ceria can reduce the activation energy of aromatic ring hydrogenation, thereby enabling guaiacols to generate the corresponding hydrogenated products with high selectivity. Response surface optimization experiments indicated that temperature and time have relatively more significant effects on the 2-MCH yield. Moreover, the Ru1/o-CeO2-ov catalyst exhibited excellent reusability, and was extensively applicable to the hydrogenative dearomatization of different types of lignin-derived phenols, providing a unique solution for upgrading biomass feedstock into specific structural chemicals.
危险品化学品经营许可证（带存储）