Oxidative Adsorption Desulfurization Of Fuels And Catalytic Alkane Dehydrogenation Over Earth-abundant Metal Oxides

This work aims to explore low-cost and active metal oxides for the oxidative-adsorptive desulfurization,which is more selective than the sole adsorptive desulfurization in multi-component system,and catalytic alkane dehydrogenation that is typically catalyzed by precious Pt catalysts.This work,which is in the field of separation and chemical engineering,is of great importance for the acedamic research and practical use.A novel desulfurization method was proposed in this work by combining photocatalytic desulfurization and adsorptive desulfurization at ambient conditions.The thiophenic compounds were oxidized to sulfones and eventually adsorbed on the BiVO₄/C₃N₄@SiO₂materials.By utilizing visible light,the coupled desulfurization method greatly improved the S-capacity compared to the sole adsorptive desulfurization with the capacity of7.4mg-S/g-sorb.The rapid oxidative adsorption desulfurization witouht light radiation was deveopled.The well-dispersed Ti/SiO₂ materials were able to catalyze the oxidation of thiophenic compounds at RT and significantly enhanced the desulfurization activity in real diesel system.The movable lattice oxygen of AgO_x in Ag/SiO₂ adsorbents could act as a solid oxidant and show a great ODS performance for several thiophenic compounds in the air at 25? without any addition of liquid oxidants.The catalytic dehydrogenation behavior of WO₃ domains on ZrO₂ were investigated.WO₃ with intermidiate oxidation state was most active in PDH reaction.The over-carburized W₂C phase is inactive for PDH.H₂ can stabilize the surface of catalyst in the reaction.It is promising for W based catalyst in industrial use due to its comparable PDH activity and cyclic period to commercial Cr catalysts.The innert TiO₂ was introduced to WO₃ system to modify its properties in PDH.The enhancement of W dispersion and the decrease of W reducibility lead to the improvement of activity and selectivity of W-TiO₂ samples for PDH reaction.The dehydrogenation rate per mass of W-TiO_x catalyst was 2 times higher than the WO₃/ZrO₂ system.The unreducible metal oxides were employed to PDH and they were more stable due to their stable oxidation state.High surface area is the key for the PDH activity of unreducible metal oxides and their activity was as about 4-5 times as that in Cr system with the selectivity larger than 95%.