氢气中氧气的钯催化去除

Elimination of Oxygen from Hydrogen with Catalysis of Palladium

以活性氧化铝为载体，采用超声波浸渍法制备不同钯含量的催化剂，用于氢气中微量氧气的去除．研究了反应过程中催化剂钯含量和氢气空速对出口氧气含量的影响，采用红外热成像方法对催化床层反应区域进行了检测．研究发现，随空速增大，氧气转化率降低；出口氧含量曲线在空速为10～12s^-1和15～17s^-1两处出现拐点，且钯含量越高，拐点越明显．这些现象表明：在氢氧催化反应中，内扩散为反应的主要控制步骤；当钯含量高于0．20％时，提高钯含量对催化反应影响不明显；采用较低的钯含量、较小的颗粒、较大的催化剂装填量有利于提高除氧反应效率．

Palladium catalysts with different contents of palladium supported by activated Al2O3 were prepeared by means of ultrasonic impregnation to eliminate trace oxygen from hydrogen. The effects of the palladium content and the H2 space velocity on the O2 content after the reaction were then discussed. Moreover, the reaction region on the catalyst bed was detected by means of infrared thermal imaging. The results show that the conversion of O2 decreases with the increase of H2 space velocity, and that two inflection points occur at the H2 space velocities of 10 - 12s^- 1 and 15 - 17s^-1, respectively, which become more acuate at a higher palladium content. It is thus concluded that the internal diffusion is the controlling step of the catalytic reaction, that the reaction is not sensititive to the palladium content more than 0. 20%, and that the catalytic reaction becomes more effective in the conditions of low palladium content, small catalyst particle size and large catalyst dosage.