A Self-Separating Multiphasic System for Catalytic Hydrogenation of CO2 and CO2-Derivatives to Methanol

Abstract

Catalytic conversion of CO2 and hydrogen to methanol was achieved in a self-separating multiphasic system comprising the tailor-made complex [Ru(CO)ClH(MACHO-C12)] (MACHO-C12=bis{2-[bis(4-dodecylphenyl)phosphino]ethyl}amine) in n-decane as the catalyst phase. Effective catalyst recycling was demonstrated for the carbonate and the amine-assisted pathway from CO2 to methanol. The polar products MeOH or MeOH/H2O generated from the catalytic reactions spontaneously formed a separate phase, allowing product isolation and catalyst separation without the need for any additional solvent. In the amine-assisted hydrogenation of CO2, the catalyst phase was recycled over ten subsequent runs, reaching a total turnover number to MeOH of 19200 with an average selectivity of 96 %.