SiO_(2)包覆膜对介孔Pd/SiO_(2)催化蒽醌加氢制备双氧水的作用  

Effect of Thin SiO_(2) Film Coating Pd on Mesoporous Pd/SiO_(2) Catalyzing Hydrogenation of Anthraquinone to Prepare H_(2)O_(2)

作　　者：李大卫 王树东[2] 苏宏久[2] 严华 LI Dawei;WANG Shudong;SU Hongjiu;YAN Hua(Energy College,University of Chinese Academy of Sciences,Beijing 100049,China;Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China)

机构地区：[1]中国科学院大学能源学院,北京100049 [2]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《材料导报》2023年第24期244-248,共5页Materials Reports

摘　　要：本工作以2-戊基蒽醌生产过氧化氢的反应过程为研究背景,使用平均孔径为12 nm的介孔球形氧化硅载体,利用强静电吸附(SEA)法制备了Pd/SiO_(2)催化剂,并使用四乙氧基硅烷包覆催化剂所负载的Pd颗粒,制备出用于蒽醌加氢的Pd@SiO_(2)/SiO_(2)球形颗粒催化剂。相较于未经包覆修饰的Pd/SiO_(2)球形催化剂,Pd@SiO_(2)/SiO_(2)催化剂表现出较高的100%选择性,以及高加氢活性,时空产率高出16.4%;同时,利用物理吸附(BET)、粉末X射线衍射(XRD)、透射电镜(TEM)、H_(2)-TPR、XPS等手段对所制备的Pd@SiO_(2)/SiO_(2)及Pd/SiO_(2)催化剂进行表征,可观察到经包覆后,Pd颗粒表面有0.1 nm左右的SiO_(2)膜,催化剂的比表面积和孔容相较于载体有所增加,而孔径则减小;H_(2)-TPR及XPS表征结果则显示,在Pd@SiO_(2)/SiO_(2)上,由于SiO_(2)薄膜的包覆作用,Pd@SiO_(2)/SiO_(2)的Pd~0物种的结合能更高,Pd颗粒与载体间的相互作用更强;上述制备方法均使得Pd@SiO_(2)/SiO_(2)催化剂表现出较高的选择性及活性。Based on the background of the hydrogenation of anthraquinone to produce hydrogen peroxide,Pd/SiO_(2) catalyst was prepared using mesoporous spherical silica support with an average pore diameter of 12 nm by strong electrostatic adsorption(SEA)method,and Pd particles supported on the catalyst were coated with TEOS to prepare Pd@SiO_(2)/SiO_(2) spherical particle catalyst for anthraquinone hydrogenation as well.Compared with unmodified Pd/SiO_(2) spherical catalyst,Pd@SiO_(2)/SiO_(2) catalyst showed better hydrogenation activity,and the space-time yield was 16.4%higher than that of Pd/SiO_(2).Besides,it also exhibits 100%selectivity.The prepared Pd@SiO_(2)/SiO_(2) and Pd/SiO_(2) catalysts were characterized by physical adsorption(BET),powder X-ray diffraction(XRD),transmission electron microscopy(TEM),H_(2)-TPR,XPS.After coating,it can be seen that the Pd particle surface has a thin SiO_(2) film of 0.1 nm,and the specific surface area and pore volume of the catalyst increase,compared with the support,while the pore size decreases.The H_(2)-TPR and XPS characterization results show that,due to the coating of SiO_(2) film,the binding energy of Pd 0 species on Pd@SiO_(2)/SiO_(2) is higher,and the interaction between Pd particles and carriers is stronger.The above methods make Pd@SiO_(2)/SiO_(2) catalyst shows higher selectivity and activity.

关 键 词：介孔氧化硅材料 双氧水 蒽醌加氢 钯贵金属催化 氧化硅包覆 高选择性 高活性 

分 类 号：TQ11[化学工程—无机化工]