摘要
以H_2S和CS_2作硫化剂,用TPS和TPDS方法研究了水媒气变换催化剂CoMoK/γ-Al_2O_3的硫化及反硫化过程。用H_2S/H_2硫化时,只发现H_2S的消耗和H_2O的生成,用CS_2/H_2硫化时,首先生成CO_2,然后是CH_4,H_2O和H_2S,TPG实验表明催化剂表面上有积炭,造成催化剂的活性降低。但积炭在水煤气变换反应进行中逐渐除去。TPDS实验表明N_2不起反硫化作用,H_2和CO也没有明显反硫化作用,H_2O对CoMoK/γ-Al_2O_3催化剂有根强的反硫化作用。O_2能使催化剂部分永久性失活。XPS测试表明反硫化的催化剂中低价的Mo ̄(4+)转变成高价的Mo ̄(5+)和Mo ̄(6+),导致其活性下降。
The sulfurization and desulfurization of water gas shift catalyst CoMoK/Al2O3have been investigated by TPS and TPDS techniques, using H_2S and CS_2 as sulfurizingagents. Only H_2S consumption and H_2O formation were found when the catalyst was sulfur-ized with H_2S/H_2. When CS_2/H_2 was used as sulfurizing agent,CO_2 was formed at first,then CH_4,H_2O and H_2S as shown by TPS curves. Carbon deposition on the catalyst duringthe sulfurization with CS_2/H_2 caused lowering of the catalytic activity, but the deposifed car-bon could be reduced in the run of WGS reaction. The results of TPDS indicated that N_2 doesnot act in desulfurization and H_2 or CO also does not give an obvious effect on the desulfur-ization. However,H_2O shows a strong desulfurizing effect. Oxygen caused a permanent lossof the activity in some part of the catalyst. XPS results showed that Mo ̄(4+)has been changedto Mo ̄(5+)and Mo ̄(6+)in desulfurized catalyst,decreasing its activity.
出处
《应用化学》
CAS
CSCD
北大核心
1994年第2期62-66,共5页
Chinese Journal of Applied Chemistry
关键词
水煤气
催化剂
变换
硫化
反硫化
CoMoK/Al2O3,water-gas,catalyst,sulfurization,desulfurization