M @ SiO ₂ Controlled Synthesis And Catalytic Properties Of Core-shell Materials

A prominent advantage of carbon materials prepared by the hydrothermalcarbonization process is that the material owning-OH, C=O and C=C rich functionalgroups on the surface. So as template to synthesize the core-shell or a more complexmaterial. Due to the structural characteristics of the core-shell material have thepotential application as a catalytic material in the field of catalysis. Therefore, theCuO@SiO₂core-shell materials were prepared and CO oxidation and CO+NO reactionas a probe to study the catalytic performance. There are three different methodspreparing CuO@SiO₂core-shell materials, first synthesized copper carbon spheresprecursor: one-step synthesis of carbon composite copper; Second, two-step synthesis ofcopper-carbon composite material; Third, carbon spheres loading copper metal. Thenthe coating silicon layer on the surface obtaining the CuO@SiO₂core-shell materialsThe structure of the catalyst was characterized by SEM, TEM, N2adsorption-desorption and ICP-OES that the results show that the catalyst prepared bythree methods have formed a hollow shell structure, and the size is2μm,240and about250nm, the BET is10,85and223m2·g-1, the copper content is36%,26%and5%,respectively. The species of the catalyst were characterized by XRD, H2-TPR, CO-TPR,CO-TPD, NO-TPD, IR and UV-vis characterization, and the results show that thecopper species exists as the form of copper oxide, and there are different sizes copperoxide particles. The core-shell materials catalyst not only have lower temperaturereduction peak for CO and H2, there is also more CO adsorbtion peaks and lowertemperature NO desorption peaks. And CO oxidation, CO+NO, benzyl alcoholoxidation reaction are used to evaluate its catalytic performance, compared with othermethods CuO/SiO₂composites core-shell materials have better catalytic performance.