【摘要】 采用ZrO2负载的RuOx催化剂在低温(如373 K)下催化甲醇选择氧化合成甲酸甲酯,发现RuOx的结构可显著影响反应速率和产物选择性.在相近的甲醇转化率下,RuO42-物种的催化活性和对甲酸甲酯的选择性明显高于RuO2物种,表明在ZrO2表面构筑高活性高选择性的RuO42-结构有利于获得高的甲酸甲酯产率.更多还原

【Abstract】 The oxidation of methanol to methyl formate at low temperature（373 K） over the ZrO₂-supported RuO_x catalyst was studied.The methanol oxidation rate and product selectivity strongly depend on the RuO_x structure,which is changed in the Ru surface density range of 0.2-3.8 Ru/nm².The RuO_x structure evolves from isolated RuO^2-₄ species below 0.4 Ru/nm² to RuO₂ clusters above 1.9 Ru/nm².Such structural evolution with increasing Ru surface density leads to a decrease in the methanol oxidation rate on per Ru atom and on per exposed Ru atom（i.e.turnover rate）.This reveals that RuO^2-₄ species are more reactive than RuO₂ species,which is consistent with the higher reducibility of the RuO^2-₄ structure.These RuO^2-₄ species are also more selective than the RuO₂ species for the methyl formate formation at similar methanol conversion;a ～96% methyl formate selectivity（at ～15% methanol conversion） was attained at 0.2 Ru/nm² with predominant RuO^2-₄ structure.These findings suggest that the highly active and selective RuO^2-₄ structure is required for achieving high methyl formate productivity.更多还原