Determination of the prevailing -butenes dimerization mechanism over nickel containing Al-MCM-41/ZSM-5 mixed-phase catalysts

Nickel modified mixed-phase catalysts containing both mesoporous Al-MCM-41 and microporous ZSM-5 phases were synthesized via a one-pot synthesis. By varying the composition of the catalysts, optimum values regarding Si/Al ratio and nickel content for a highly selective dimerization of n -butenes were identified. An interaction of nickel sites with vicinal aluminum or acid sites can be assumed, since a correlation between Ni/(Al + Ni) ratio, catalytic activity and selectivity was found. Novel approaches to evaluate the contribution of the cationic or coordinative reaction mechanism to the overall reaction course are proposed. Novel approaches to evaluate the contribution of the cationic or coordinative reaction mechanism to the overall reaction course are proposed.