Effect of nickel promoter on solvent-free sulphated zirconia catalyst for the esterification of acetic acid with n-butanol

A simple solvent‐free preparation method was used to synthesize sulphated zirconia catalyst with various amounts of nickel promoter. This research investigated the effect of nickel addition to sulphated zirconia on the catalyst performance in esterification of acetic acid (a bio‐oil model) with n‐butanol. The results show that the addition of nickel contributed to the increase of sulphur content that bonded with nickel, the increase of thermal stability of the catalysts, and the formation of additional sulphate groups, and thus resulted in better catalytic performance compared to sulphated zirconia without nickel. More nickel being added resulted in a significant increase of acetic acid conversion; with 0.05 mol/mol nickel amount, the conversion was 97.93 %. This result represents a dramatic increase of about 2 and 3 times compared to the conversions of non‐nickel sulphated zirconia catalyst and non‐catalyst reactions, respectively.