V_2O_5/Ti-Ce-PILC在H_2S选择性催化氧化过程中的催化性能

Catalytic performance of V_2O_5/Ti-Ce-PILC in the selective oxidation of H_2S

合成了TiO_2-CeO_2柱撑黏土负载V_2O_5催化剂,通过XRD、氮气吸附脱附、TG、FT-IR、H_2-TPR、NH_3-TPD、XPS等方法对其物理化学性质进行了表征,研究了该催化剂在H2S选择性催化氧化反应中的活性。结果表明,负载5%V_2O_5的TiO_2-CeO_2柱撑黏土在180℃下催化效果最好,且尾气中不含SO_2。V_2O_5、TiO_2和CeO_2之间的相互作用提高了催化剂的活性,CeO_2提高了催化剂的热稳定性,同时提供大量晶格氧,加强了V_2O_5的氧化还原作用,降低了反应温度;TiO_2加强了VO_x和CeO_x的再氧化,降低了硫酸盐的覆盖率,从而降低了催化剂的失活速率。

A series of V_2O_5 doped Ti-Ce-pillared clays(V_2O_5/Ti-Ce-PILC) were prepared and characterized by XRD,nitrogen physisorption,FT-IR,XPS,H_2-TPR,TG and NH_3-TPD. The catalytic performance of V_2O_5/Ti-Ce-PILC in the selective oxidation of H_2S was investigated in a fixed bed reactor. The results illustrated that 5% V_2O_5 doped Ti-Ce-pillared clays performs well at 180 ℃ in the selective oxidation of H_2S,which can be ascribed to the interaction among V_2O_5,TiO_2 and CeO_2. CeO_2 can enhance the catalyst thermostability and supply more lattice oxygen,which is of benefits to the redox of V_2O_5 and the decrease of reaction temperature.Meanwhile,the addition of TiO_2 may promote the reoxidation of VOx and CeOx and reduce the sulfate coverage,which can then postpone the catalyst deactivation.