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用硫酸镍制备植物油加氢催化剂,虽可以降低成本,但催化剂容易中毒。为了分析催化剂中毒的原因,XRD 实验表明,用硫酸镍制备催化剂时,催化剂中残存SO_4~(2-),高温还原时产生H_2S.H_2S 与活性镍反应生成Ni_3S_2.EXAFS 实验表明,在Ni_3S_2中。Ni 的3CN 空穴被S 原子嵌入,而Ni 的3CN 空穴是吸附H_2的活性位置,被S 原子占据后,使催化剂活性降低。因此用硫酸镍制备催化剂的关键步骤是在高温还原前除去催化剂中残存的SO_4~(2-)。
Preparation of vegetable oil hydrogenation catalyst with nickel sulfate, although it can reduce costs, but the catalyst is easily poisoned. In order to analyze the causes of catalyst poisoning, XRD results show that when nickel sulfate is used as catalyst, residual SO_4 ~ (2-) can be found in the catalyst and H_2S can be produced when it is reduced by high temperature. Reaction of H_2S with activated nickel leads to Ni_3S_2.EXAFS experiments show that in Ni_3S_2. The 3CN holes of Ni are embedded in S atoms, while the 3CN holes of Ni are the active sites for H 2 adsorption, which are occupied by S atoms to decrease the activity of the catalyst. Therefore, the key step in the preparation of catalyst with nickel sulfate is to remove the residual SO 4 2- in the catalyst before reduction at high temperature.