Preparation Of Supported Catalysts For Co₂Direct Methylation And Process Strengthen

Dimethyl carbonate (DMC) has been used as a green organic solvents andchemical materials. At present, the traditional synthetic methods of DMC extensivelyhave defect that catalyst activity or selectivity and DMC yield are relatively low.Recently, direct synthesis of DMC from industrial waste gas CO2and CH3OH becamean attractive synthetic approach due to the fact that technology is relatively simple andgreen. The synthesis of DMC as a friendly environment and operational safety and highyield new way attracted widespread attention in chemical filed.This work first systematacially studied compositions and reaction conditions ofH3PW12O40/CexTi1-xO2catalyst active ingredient, and further optimized the catalyticreaction conditions, explored to different structures of TiO2, Al2O3and porous nickelnanotube arrays by loading H3PWO40/CexTi1-xO2catalyst to those substrates usingsol-gel method and heating suspension coating. On this basis, this paper also searchednew ideas to improve the efficiency of the catalytic reaction by the electric fieldstrengthen. The results of study are as following:①H3PW12O40/CexTi1-xO2catalysts were prepared using a sol-gel method andregulated this system. H3PW12O40/CexTi1-xO2as a bifunctional catalyst was notconducive to the synthesis of DMC under mightily acid and alkaline conditions. Afterattentive disscussed, when x=0.1and the amount of ammonia is7.5mL,H3PW12O40/CexTi1-xO2showed a better catalytic performance.②Series of nano array structures of TiO2, Al2O3and porous nickel substrates wereprepared, complex catalysts were prepared by loading H3PW12O40/CexTi1-xO2catalystactive component to those substrates by sol-gel method and heating suspension coating.Interaction of active component and substrate were also investigated. XRD testindicated that H3PW12O40/CexTi1-xO2catalyst easily supported to the112crystal surfaceof rutile. NH3-TPD characterization revealed that active component of catalyst particlesmainly combined with substrate by acid site. The effect about structure of substrate andcatalytic performance of composite catalysts were investigated. Experiment resultsshown that structure of substrate changes with voltage increases in the preparationprocess of TiO2and Al2O3nanotube arrays substrate, grass structure of nano-arraysubstrate was more conducive to load.The utilization efficiency of catalysts wereenhanced after supported, reaction flux of active ingredient improved significantly6 times. Because the catalyst more significant reunion by loading to porous nickelsubstrate, which reactivity enhance relatively small.③The study also explored new ideas to improve the efficiency of the catalyticreaction by the electric field strengthen, liquid phase direct current electrolysis and highvoltage discharge skills been used to catalyzed and activated methanol and CO2forsynthesis of DMC. Liquid phase direct current electrolysis results indicated that theelectrode material, time and other factors directly affect the electrolysis products. Highvoltage discharge technology was first applied to the system of DMC synthesis,experiment results revealed that coupling efficiency of electric field and interface has asignificant impact on reactivity, regulation of interfacial reaction has a crucialsignificance in the synthesis of DMC.