Pd/PA-Ca催化剂低温催化苯甲醛氧化制备苯甲酸  

Oxidation of benzaldehyde to benzoic acid catalyzed by Pd/PA-Ca catalyst at low temperature

作　　者：黄久云 刘英[1] 李晔昕 张勋高[1] Huang Jiuyun Liu Ying Li Yexin Zhang Xungao(College of Chemistry and Molecular Sciences, Wuhan University ,Wuhan 430072, Hubei, Chin)

机构地区：[1]武汉大学化学与分子科学学院,湖北武汉430072

出　　处：《工业催化》2017年第4期41-46,共6页Industrial Catalysis

基　　金：湖北省自然科学基金(2013CFB291)资助项目

摘　　要：以植酸钙(PA-Ca)为载体、H2Pd Cl4为前驱体、甲醇为还原剂,制备了PA-Ca负载Pd的Pd/PA-Ca催化剂,对其进行XRF、BET、SEM、TEM、XRD和XPS表征,并用于苯甲醛氧化制备苯甲酸反应,考察催化剂用量、反应温度和溶剂种类对催化剂催化性能的影响。结果表明,催化剂中负载Pd质量分数为1.03%,钠质量分数为1.05%;合成的PA-Ca载体为晶化程度较低的介孔材料,比表面积为18.85 m^2·g^(-1);催化剂活性物种为Pd0和PdO。在催化剂用量n(苯甲醛)∶n(Pd)=2 000∶1、乙腈作溶剂、O_2压力101.325 k Pa(流速20 m L·min^(-1))、反应温度30℃和反应时间4 h条件下,苯甲醛转化率为83%,苯甲酸选择性为100%;催化剂具有较好的稳定性,可循环使用3~4次。A novel catalyst （PA-Ca） was prepared by （Pd/PA-Ca） of palladium nanoparticles supported methanol reduction of palladium chloride acid. The on phytic acid calcium as-prepared catalyst was characterized by XRF, BET, SEM, TEM, XRD and XPS. Pd/PA-Ca catalyst was applied in the oxidation of benzaldehyde. The effects of catalyst amounts, reaction temperatures and solvent types on the catalytic performance of Pd/PA-Ca catalyst were investigated. The results indicated that the mass fraction of Pd and Na in the catalyst were 1.03% and 1.05% ,respectively;the prepared PA-Ca support was a typical meso- porous material with low crystallization and the specific surface area of 18.85 mE ·g^- 1 ;the active species in the catalyst were Pd^0 and PdO. The conversion of benzaldehyde and the selectivity to benzoic acid were 83% and 100% ,respectively under the condition as follows：n（benzaldehyde）： n（Pd） =2 000：1 ,acetonitrile as the solvent,O2 pressure 101. 325 kPa and flow rate 20 mL· min^-1 ,reaction temperature 30 ℃ and reaction time 4 h. The catalyst exhibited good stability and could be reused （3 -4） times.

关 键 词：催化化学 苯甲醛氧化 苯甲酸 Pd/PA-Ca催化剂 低温催化 多相催化 

分 类 号：O643.36[理学—物理化学] TQ245.12[理学—化学]