摘要
Oxidative desulfurization(ODS)is a promising technology to produce clean fuel with requiring superior catalysts to lower kinetic barriers.Although most ODS catalysts are based on crystalline transition-metal oxides(TMOs),extraordinary activity also can be achieved with amorphous TMOs.However,the origin of the remarkable catalytic activity of the amorphous TMOs remains greatly ambiguous.Here,we found the crucial role of Mo–O covalency in ruling the intrinsic catalytic activity of amorphous molybdenum oxides(MoO_(x)).Experimental and theoretical analysis indicated that the nonequivalent connectivity in the amorphous structure strongly enhanced Mo–O covalency,thereby increasing the content of electrophilic oxygen and nucleophilic molybdenum to favor the MoO_(x)–H_(2)O_(2) interaction.With the boosted Mo–O covalency to improve the flexibility of the charge state,the amorphous MoO_(x)-based composite catalyst(PE-MoO_(x)/S-0.05)exhibited outstanding catalytic activity for ODS of fuel oil.The turnover frequency(TOF)value of the catalyst(18.63 h^(-1))was almost an order of magnitude higher than that of most reported crystalline MoO_(x)/molecular sieve composite catalysts.The in-depth understanding of the origin of the amorphous TMOs activity for ODS provides a valuable reference for developing ODS catalysts.
基金
supported by the National Natural Science Foundation of China(51978178,52270064,and 51521006)
the Department of Science and Technology of Guangdong Province of China(2022A1515010226)
the Program for Innovative Research Teams of Guangdong Higher Education Institutes of China(2021KCXTD043)
Key Laboratory of Petrochemical Pollution Control of Guangdong Higher Education Institutes(KLGHEI 2017KSYS004)
the Science and Technology Innovation Program of Hunan Province of China(2021RC2058)
the Startup Fund of Guangdong University of Petrochemical Technology(2018rc63)。
