Alkali metal pollutants are often regarded as toxic agents for the catalytic hydrodeoxygenation(HDO)of biomass,hindering the conversion of biomass towards higher-value hydrocarbon fuels.In this study,a series of Pt/WO...Alkali metal pollutants are often regarded as toxic agents for the catalytic hydrodeoxygenation(HDO)of biomass,hindering the conversion of biomass towards higher-value hydrocarbon fuels.In this study,a series of Pt/WO_(x)catalysts for HDO with varying K contents were synthesized,and an intriguing effect of K on activity was observed.The introduced K+occupies the H position of the hydroxyl group,poisoning Brùnsted acid sites(BAS);however,it regulates the adsorption of olefin intermediates,consequently facilitating the whole HDO reaction.Notably,dissociated hydrogen species on the metal sites can spillover to adjacent WO_(x)sites,liberating the hydroxyl group poisoned by K and thus operando forming BAS again(back to 84%of the K-free catalyst),which safeguards the dehydration step from alkali metal severe poisoning.By comparing the catalytic behavior on WO_(x)with non-reducible acidic Si-Al zeolite supports,we demonstrate that this‘deliverance effect'depends on the reducibility of the supports.The optimal 0.2 Pt0.8K/WO_(x)catalyst exhibited 2.6 times higher catalytic activity than 0.2 Pt/WO_(x),which also finds its applicability on other noble metals like Ru and Pd,achieving excellent yields across various lignin derivatives.This work not only reports an efficient K-doped Pt catalyst design for HDO reaction but also provides a more comprehensive understanding of the catalytic role of K additives on acid and metal sites.展开更多
基金supported by the“Leading Goose”R&D Program of Zhejiang(2023C01110)。
文摘Alkali metal pollutants are often regarded as toxic agents for the catalytic hydrodeoxygenation(HDO)of biomass,hindering the conversion of biomass towards higher-value hydrocarbon fuels.In this study,a series of Pt/WO_(x)catalysts for HDO with varying K contents were synthesized,and an intriguing effect of K on activity was observed.The introduced K+occupies the H position of the hydroxyl group,poisoning Brùnsted acid sites(BAS);however,it regulates the adsorption of olefin intermediates,consequently facilitating the whole HDO reaction.Notably,dissociated hydrogen species on the metal sites can spillover to adjacent WO_(x)sites,liberating the hydroxyl group poisoned by K and thus operando forming BAS again(back to 84%of the K-free catalyst),which safeguards the dehydration step from alkali metal severe poisoning.By comparing the catalytic behavior on WO_(x)with non-reducible acidic Si-Al zeolite supports,we demonstrate that this‘deliverance effect'depends on the reducibility of the supports.The optimal 0.2 Pt0.8K/WO_(x)catalyst exhibited 2.6 times higher catalytic activity than 0.2 Pt/WO_(x),which also finds its applicability on other noble metals like Ru and Pd,achieving excellent yields across various lignin derivatives.This work not only reports an efficient K-doped Pt catalyst design for HDO reaction but also provides a more comprehensive understanding of the catalytic role of K additives on acid and metal sites.
