V-Sn氧化物催化甲苯气相氧化制苯甲醛
Gas Phase Catalytic Oxidation of Toluene to Benzaldehyde over V-Sn Oxide Catalysts
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摘要: 采用溶液混合法和浸渍法制备了一系列 V2 O5- Sn O2 二元氧化物和 V2 O5- Sn O2 / η- Al2 O3 负载型催化剂 .V2 O5与 Sn O2 构成的二元氧化物样品与单氧化物及其 V2 O5- Sn O2 / η- Al2 O3 的性质不同 .负载型催化剂的活性明显高于二元氧化物样品的活性 ,甲苯转化率和苯甲醛选择性与催化剂的组成有较好的对应关系 .随着 Sn O2 的引入 ,催化剂活性缓慢降低 ,苯甲醛的选择性逐渐减小 ,可见 Sn O2 不适合作为甲苯氧化反应的催化剂组分 .XAbstract: A series of V-Sn mixed oxide and V 2O 5-SnO 2/η-Al 2O 3 catalysts with various atomic ratios of V to Sn were prepared by a solution-mixing and dipping method. It has been found that the binary oxides V 2O 5-SnO 2 show a series of properties different from that of single oxides and supported V 2O 5-SnO 2/η-Al 2O 3 catalysts. V 2O 5-SnO 2/η-Al 2O 3 catalysts displayed high catalytic activities and good selectivity to benzaldehyde under the experimental conditions used. When SnO 2 content increases, the activity decreases, the selectivity to benzaldehyde also decreases. It therefore seems unsuitable for SnO 2 to be used as a catalyst constitution for the toluene oxidation reaction. The main role of SnO 2 in the above samples is to provide a host lattice for the dispersion of vanadium, as has been proved by XRD.
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