Understanding the Effects of Electronic Properties of Ni in Zeolites and Metal Organic Frameworks on its Activity for Butene Dimerization

Linear olefins have attracted industrial attention as a basic feedstock and important intermediate in the production of polyethene and plasticizers. Butene dimerization on zeolite or metal organic framework supported Ni based catalysts represents an appealing route to selectively synthesize linear olefins from undervalued cracking fractions. Despite constituting isolated Ni sites, the rate of butene dimerization varies substantially depending upon the catalyst support and shows the following trend: Ni-FAU >> Ni-CHA > Ni-MFI >> Ni-UiO-66. We hypothesize that the local chemical environment and the electronic properties of Ni encapsulated in different supports impact the activation of butene thereby resulting in substantially different rates for butene consumption. We therefore propose to investigate the structural and electronic properties of Ni in a series of Ni-CHA, Ni-MFI, Ni-FAU, and Ni-UiO-66 catalysts, with varying Ni content, via HERFD-XANES, VtC-XES, and EXAFS measurements.