34 research outputs found
Studies on CuCe0.75Zr0.25Ox preparation using bacterial cellulose and its application in toluene complete oxidation
A series of CuCe0.75Zr0.25Ox catalysts (CCZ) were synthesized based on the environmentalâfriendly bacterial cellulose (BC) by using the solâgel method. The corresponding synthesis mechanism, physicochemical properties of the catalysts and catalytic performances for toluene oxidation were comprehensively studied. In the presence of BC without sugar, the CCZâA synthesized by ethanolâgel exhibits better catalytic activity than the CCZâW synthesized by waterâgel, which may be due to the different roles of BC in different solvents. However, it is worth noting that the graft copolymerization between BC and active metal (Ce4+, Cu2+) is the same process in both waterâgel and ethanolâgel. The activity of CCZâSW synthesized by waterâgel using BC with sugar is obviously higher than that of CCZâW and CCZâA. The temperature of complete degradation of toluene over CCZâSW is 205â°C, which is 35â°C lower than that of CCZâW. The results from BET, Raman and H2âTPR indicate that the larger the specific surface area, the more oxygen vacancies and better lowâtemperature reducibility, that are mainly responsible for the excellent activity of CCZâSW. The existence of sugar in BC could hinder the agglomeration of active metal particles during the calcination process. Combined with the results of inâ
situ DRIFT, the adsorbed toluene on the catalyst surface is oxidized into alkoxide, aldehydic and carboxylic acid species as intermediates before the complete oxidation into CO2 and H2O.
Catalysing sustainable fuel and chemical synthesis
Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this centuryâs grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands