Nb2O5纳米材料在催化氢化肉桂醛中的影响

使用Nb2O5纳米线（W-Nb2O5）和介孔Nb2O5（S-Nb2O5）两种载体负载金属Pd，制备了Pd/W-Nb2O5和Pd/S-Nb2O5两种催化剂对肉桂醛(CMA)进行催化还原，考察了催化剂的活性和选择性。以乙醇为反应溶剂，催化剂用量0.10 g，80 oC，2MPa H2压力下反应6 h，Pd/W-Nb2O5对CMA的转化率为99%，HCMA的选择性为65%。Pd/S-Nb2O5在相同条件下反应， CMA转化率为98%，HCMA选择性为84%。W-Nb2O5表面酸性过强，导致HCMA选择性变低。继续考察Pd/S-Nb2O5在不同条件下对CMA加氢反应的影响。结果显示温度，H2压力，催化剂载体Nb2O5的晶化温度对反应均有影响。

Influence of Nb2O5 Nanomaterial in Hydrogenation of Cinnamicaldehyde

Nb2O5 nanowires and mesoporous Nb2O5 were used as the catalyst supports to prepare Pd/W-Nb2O5 and Pd/S-Nb2O5 which used in hydrogenation reaction of Cinnamicaldehyde(CMA) to hydrocinnamaldehyde(HCMA), the conversion and selectivity is investigated. Reaction was carried out using ethanol solvent, catalyst 0.1 g, 80 oC, 2 MPa H2 pressure, 6 h reaction time, Pd/W-Nb2O5 have a conversion about 99%, Selective of HCMA is about 65%. Under the same reaction conditions, Pd/S-Nb2O5 has a conversion about 98%, the selective is about 84%. Too more acidity sites on W-Nb2O5 surface cause more side reactions and low selective of HCMA. Reaction temperature, H2 pressure, thermal treatment temperature of the supports can influence the reaction conversion and selective. Increasing the temperature or H2 pressure can enhance the reaction conversion. But high thermal treatment temperature make the Pd/S-Nb2O5 lose the catalyst activity on account of higher crystallinity of Nb2O5 and lower acidity on the surface.