疏水性铂催化剂常温氢氧复合性能  

Performance of Hydrogen Oxygen Recombination on Hydrophobic Pt catalysts at Ambient Temperature

作　　者：汤卫华[1] 吴文宏[1] 张琪[1] 

机构地区：[1]中国船舶重工集团公司第七一八研究所,河北邯郸056027

出　　处：《精细化工》2017年第4期418-423,共6页Fine Chemicals

摘　　要：以OTMS(十八烷基三甲氧基硅烷)为Al_2O_3载体表面修饰剂、H2Pt Cl6异丙醇溶液为浸渍液,通过真空浸渍还原法制备了疏水性Pt催化剂,改变修饰液中OTMS质量分数得到了3种疏水性催化剂Ⅱ、Ⅲ和Ⅳ。利用XRD、FTIR和SEM对催化剂进行了表征,采用接触角测量仪考察了催化剂的疏水性能;在干燥、高湿及水相环境中分别对催化剂进行了氢氧复合性能评价;通过BET和脉冲氢氧滴定对催化剂的活性比表面积和Pt分散度进行了测量。结果表明:与未进行OTMS修饰的催化剂Ⅰ相比,催化剂Ⅱ可以在高湿条件下保持相对稳定的氢氧复合性能,氢转化率保持在96.25%,在水相环境下氢转化率在40 h内由61.25%下降至43.75%;在40 h内,催化剂Ⅲ和Ⅳ在高湿环境下氢转化率分别为93.75%和87.50%,而在水相环境下分别为76.25%和63.75%。Al2O3 was firstly modified by different mass fraction of OTMS（ n-octadecyltrimethoxysilane）in toluene solution. Three kinds of hydrophobic Pt catalyst Ⅱ,Ⅲ and Ⅳ were then prepared by vacuum impregnation-reduction with modified Al2O3 as carrier and H2PtCl6 isopropanol solution as impregnation solution. The obtained catalysts were characterized by means of XRD,FTIR and SEM. The hydrophobic properties of the catalysts were measured by contact angle measurement instrument. Subsequently,the catalytic performances of hydrogen-oxygen recombination under the conditions of dry,wet and water were studied. Finally,the active specific surface area of the catalysts and dispersity of Pt were investigated by BET and pulse hydrogen-oxygen titration techniques. The results showed that compared with catalyst Ⅰ without OTMS modification,catalyst Ⅱ exhibited a relatively stable performance of hydrogen-oxygen recombination under wet condition,and the conversion of hydrogen was 96. 25%.However,the conversion of hydrogen over catalyst Ⅱdecreased from 61. 25% to 43. 75% during the 40h-testing in the water phase. Under wet condition,the conversions of hydrogen over catalyst Ⅲ and catalyst Ⅳ were 93. 75% and 87. 50%,respectively. On the contrary,those were only 76. 25% and63. 75% under water condition during 40 hours.

关 键 词：铂 催化剂 疏水性 亲水性 氢氧复合 催化与分离提纯技术 

分 类 号：O643.3[理学—物理化学]