松香歧化用钯炭催化剂的制备

用浸渍-还原法制备了一系列Pd/C催化剂,并应用于马尾松松香歧化反应。研究了活性炭粒径大小、载体预处理、还原条件等因素对Pd/C催化剂活性的影响。结果表明:用10%H2O2和1%强氧化物G的复合氧化剂对椰壳活性炭(粒径150~250μm)进行预处理,制得的Pd/C催化剂,可以使钯利用率达到96.4%,去氢枞酸高达68.4%。通过X射线光电子能谱(XSP)测定Pd/C中钯化合价的分布。甲醛过量1倍时,有44.4%Pd2+被还原成金属钯,且有24.9%的Pd4+生成。通过优化条件所制备的Pd/C催化剂活性明显高于其它厂家同类催化剂活性,并已应用于工业化生产。

Preparation of Pd/C Catalyst Used for Disproportionation of Rosin

A series of Pd/C catalysts were prepared by impregnation-reduction method, and used for the disproportionation of Masson′s pine rosin. Factors influencing Pd/C catalytic activity such as particle size, carrier pretreatment and reduction condition were studied. Results showed that the Pd/C catalyst prepard from activated carbon(AC) treated with complex oxidants(10% H_2O_2 and 1% oxidant G )can increase the utilization rate of palladium up to 96.4% and dehydroabietic acid up to 68.4%.Through X-ray photoelectron spectroscopy(XPS), the distribution of valency of Pd in Pd/C were investigated. When HCHO amount exceeded one fold, about 44.4% Pd~(2+) was reduced to metallic Pd with the formation of 24.9% Pd~(4+) found in Pd/C catalyst. The activity of catalyst prepared under the optimized experiment conditions:obviously exceeds counterparts of other companies. Furthermore, this catalyst has been produced industrially.