Ni-Zn/活性炭催化剂的程序升温还原研究

TEMPERATURE PROGRAMMED REDUCTION OF Ni Zn/C CATALYST

采用ＴＰＲ技术对甲醇、乙醇羰基化反应的Ｎｉ／Ｃ和Ｎｉ－Ｚｎ／Ｃ催化剂进行了研究．实验发现，负载于活性炭上的ＮｉＯ比非负载的ＮｉＯ容易还原；Ｎｉ与Ｚｎ之间有相互作用，Ｎｉ－Ｚｎ／Ｃ的还原峰温介于Ｎｉ／Ｃ与Ｚｎ／Ｃ之间；还原后的Ｎｉ／Ｃ和Ｎｉ－Ｚｎ／Ｃ催化剂比非负载ＮｉＯ还原后的Ｎｉ更易氧化；氧化后的Ｎｉ／Ｃ和Ｎｉ－Ｚｎ／Ｃ在相同的升温速率下再一次还原，其峰温θｍ比第一次还原时低３０～５０℃，而对Ｚｎ／Ｃ的θｍ无影响．经反复氧化－还原操作，得到不同升温速率下的ＴＰＲ谱，提出一种用ＴＰＲ谱直接计算［Ｈ２］ｍ的方法。

Temperature programmed reduction (TPR) technique was used in studying catalytic behavior of Ni/C, Zn/C, Ni Zn/C and unsupported NiO particles. The results showed that Ni/C catalyst was reduced more easily than unsupported NiO. The maximum peak temperature θ m of Ni Zn/C was between that of Ni/C and Zn/C, and the single peak indicated that the interaction between Ni and Zn apparently occurred. After reduction, the catalysts Ni/C and Ni Zn/C were oxidized more easily than unsupported NiO. The oxidized catalysts Ni/C and Ni Zn/C were easily reduced again, the θ m was lower than that of the first reduced one by 30￣50℃, but Zn/C was not influenced. A method for the calculation of H 2 concentration at the maximum peak temperature, m, was proposed from TPR profile directly. The reduction activation energy E R of the catalysts was obtained.