HYDROGENATION CO2 TO FORMIC ACID OVER RU SUPPORTED ON CARBON NANOTUBES

摘要

The use of CO2 as a carbon resource for the production of fuels and chemicals not only contributes to the alleviation of global climate changes caused by growing CO2 emissions, but also provides an attractive approach to reducing dependence on fossil fuel resources[1]. Recently, many studies have been devoted to the catalytic conversion of CO2 to light olefins, urea, methanol, acetic acid, polycarbonates, formic acid, calcium carbonate, silicon building materials, etc.. One promising route for the use of CO2 is the selective production of formic acid by the hydrogenation of CO2 [2]. To the best of our knowledge very few heterogeneous systems with solid (supported) catalysts have been investigated. Ruthenium complex catalysts immobilized on silica and polystyrene resin have been examined [3]. However, the production of these catalysts is also complicated. Ma et al. reported that optimal activity of ruthenium hydroxide as a catalyst for the hydrogenation of CO2 to formic acid is achieved over a γ-Al2O3 supported 2.0 wt% Ru, the yield of formic acid is 9.1mmol/h [4]. Compared with traditional catalyst supports, carbon nanotubes (CNTs) with high external surface area and aspect ratio display unusual behaviors, such as being able to significantly increase the contact surface between the reactants and active sites of catalysts, more hydroxyl groups and to greatly minimize the diffusion limitations [5]. Therefore, this paper report that ruthenium supported on CNTs for hydrogenation of CO2 to formic acid.