KCl对Cu-K-La/γ-Al2O3催化剂上HCl氧化反应性能的影响

采用等体积浸渍法制备了Cu-K-La/γ-Al₂O₃催化剂，考察了KCl对该催化剂催化HCl氧化制Cl₂反应性能的影响. 当KCl的负载量为5 wt%时，Cu-K-La/γ-Al₂O₃催化剂表现出较好的催化活性和稳定性，可在较大的原料气空速变化范围内使用. 在0.1 MPa，360 ℃，空速450 L/（kg-cat·h）和HCl/O₂摩尔比为2：1的反应条件下，Cu-K-La/γ-Al₂O₃催化剂上HCl转化率在100 h内保持85%以上. 表征结果表明，Cu，K和La物种均高度分散于γ-Al₂O₃载体表面；一定量KCl的加入可降低Cu²⁺ → Cu⁺的还原温度，从而提高Cu²⁺活性中心的催化活性.

Effect of KCl on the performance of Cu-K-La/γ-Al2O3 catalyst for HCl oxidation

Cu-K-La/γ-Al₂O₃ catalysts prepared by the incipient wetness impregnation for the catalytic oxidation of HCl to Cl₂ at atmospheric pressure were investigated for the effect of KCl on the catalyst performance. Cu-K-La/γ-Al₂O₃ catalyst with 5 wt% KCl loading showed good activity and stability due to the promotion by KCl. It gave good activity over a wide range of space velocity of the feed gas and conversion of HCl above 85%, and it was nearly unchanged in activity after 100 h reaction at the conditions of 0.1 MPa, 360 ℃, space velocity of 450 L/(kg-cat·h), and HCl/O₂ molar ratio = 2:1. X-ray diffraction results indicated that Cu, K, and La species were highly dispersed on the surface of the γ-Al₂O₃ support. H₂ temperature-programmed reduction results indicated that the addition of KCl favored the reduction of Cu²⁺ to Cu⁺ and improved the activity of the active sites of Cu²⁺ species for HCl oxidation.