骨架镍催化剂制备及其催化烯基芳烃加氢性能的研究

考察了成型时拟薄水铝石和合金粉的比例、胶溶剂硝酸质量分数,水粉比及焙烧温度对骨架镍催化剂侧压强度的影响,采用XRD和TG-DTA等手段对催化剂进行表征。结果表明,催化剂侧压强度随着拟薄水铝石和合金粉的比例、胶溶剂硝酸质量分数、水粉比以及焙烧温度的提高呈现先增加后减小的规律,在拟薄水铝石与合金粉质量比1.5、胶溶剂硝酸质量分数6%和水粉比0.21 mL.g-1条件下成型,860℃空气中焙烧,得到侧压强度最好的催化剂,以苯乙烯、甲基苯乙烯加氢为探针反应,对催化剂的加氢性能进行评价,结果表明,在反应压力2 MPa、温度80℃、原料空速2 h-1和V(H2)∶V(油)=300∶1条件下,苯乙烯与甲基苯乙烯在考察的500 h运转周期内,转化率接近100%,且催化剂活性保持稳定。

Preparation of Raney Ni catalyst and research on its catalytic hydrogenation performance for alkenyl aromatics

The influence of mass ratio of pseudo-boehmite to Ni-Al alloy,nitric acid concentration,mass ratio of water to powder and calcination temperature on the strength of the catalysts was investigated.The catalysts were characterized by XRD and TG-DTA.The results illustrated that the compressive strength of the catalysts increased first and then decreased with the enhancement of mass ratio of pseudo-boehmite to Ni-Al alloy,nitric acid concentration,mass ratio of water to powder and calcination temperature.The catalyst with optimal strength was prepared under the condition as follows:mass ratio of pseudo-boehmite to Ni-Al alloy 1.5,nitric acid mass fraction 6%,mass ratio of water to powder 0.21 mL·g^-1 and calcination temperature 860 ℃.The catalytic performance of the catalyst was evaluated using the hydrogenation of styrene and methylstyrene as the probe reaction.The results showed that the conversion rate of both styrene and methylstyrene could reached 100% approximately under the condition of reaction pressure 2 MPa,reaction temperature 80 ℃,reaction time 500 h,raw material space velocity 2 h^-1,and V(H₂)∶V(oil)=300∶1.Furthermore,the catalyst stability could be maintained excellently during the whole evaluation process.