Mo-V-Te-Nb-O催化剂上丙烷选择氧化制丙烯酸Ⅰ.催化剂的制备条件及稳定性

Selective Oxidation of Propane to Acrylic Acid on Mo-V-Te-Nb-O Catalyst Ⅰ. Preparation Conditions and Stability of Catalyst

研究了催化剂的制备条件 (焙烧方式、焙烧气氛和焙烧温度 )对Mo V Te Nb O上丙烷选择氧化制丙烯酸反应的影响 .结果表明 ,制备条件对催化剂的催化性能具有很大的影响 .与敞开式焙烧制得的催化剂相比 ,封闭式焙烧制得的催化剂具有较高的丙烯酸选择性 ,但丙烷转化率较低 .在空气中焙烧制得的催化剂对丙烯酸无选择性 ,但在氮气和氩气中焙烧制得的催化剂具有很高的丙烷转化率和丙烯酸选择性 .随着焙烧温度的升高 ,丙烷转化率降低 ,丙烯酸选择性升高 ,适宜的焙烧温度为6 0 0℃ .催化剂制备条件对催化剂的晶相结构也具有重要的影响 .在惰性气氛中采用 6 0 0℃下封闭式焙烧制得的Mo V Te Nb O催化剂经 2 10h反应后 ,丙烷转化率保持为 19% ,而丙烯酸选择性持续升高 ,由 32 %升至 5 0 % .

The effects of preparation conditions (calcination mode, calcination atmosphere and calcination temperature) of Mo-V-Te-Nb-O catalyst on the selective oxidation of propane to acrylic acid (AA) were studied. It was found that the preparation conditions have obvious effects on the catalytic performance of the catalyst. The catalyst calcined in closed mode exhibited higher AA selectivity but lower C 3H 8 conversion, compared with the catalyst calcined in open mode. The catalyst calcined in air showed no AA selectivity, while the catalyst calcined in N 2 or Ar exhibited high C 3H 8 conversion and AA selectivity. The C 3H 8 conversion decreased and the AA selectivity increased with the increase of temperature, the suitable calcination temperature was 600 ℃. The preparation conditions also showed significant effects on the phase structure of the catalyst. The catalyst prepared under the optimized conditions afforded C 3H 8 conversion of 19% and AA selectivity from 32% to 50%.