Although homogeneous catalytic systems have been central in ethylene oligomerization, the SiO2-Al2O3-supported nickel phosphide (Ni2P) catalyst was recently examined to be capable of transforming ethylene into higher olefins. Herein, better catalytic performance in ethylene oligomerization is achieved with Ni2P/SiO2 than Ni2P/SiO2-Al2O3 and Ni2P/Al2O3. As a factor influencing ethylene oligomerization, the particle size of Ni2P is the smallest over Ni2P/SiO2 due to strong metal-support interaction. While the oligomer productivity is affected by the density of Brønsted acid site present in the supported Ni2P catalysts, Ni2P/SiO2 has a relatively high ratio of Brønsted to Lewis acid sites. Moreover, Ni2P/SiO2 is able to easily generate and transfer hydrogen species via the Brønsted acid P[sbnd]OH groups, which would affect formation of nickel hydride species that is important in oligomerizing ethylene. Therefore, the above features of Ni2P/SiO2 are beneficial for ethylene oligomerization into higher olefins.
This work was financially supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Republic of Korea ( 2016R1A6A1A03013422 ) as well as by the Next Generation Carbon Upcylcing Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT, Republic of Korea ( 2017M1A2A2043148 ). We acknowledge technical supports from the Hanyang LINC+Analytical Equipment Center in Seoul.This work was financially supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Republic of Korea (2016R1A6A1A03013422) as well as by the Next Generation Carbon Upcylcing Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT, Republic of Korea (2017M1A2A2043148). We acknowledge technical supports from the Hanyang LINC+Analytical Equipment Center in Seoul.
