The effect of Ba, Ce, Cs and La as co-metals in Cu/γ-Al2O3 catalysts for the hydrogenolysis of glycerol into 1,2-propanediol was investigated at industrially relevant reaction conditions over time. The addition of Ba or Ce increased the initial activity per Cu0 accessible site. Apart from Cs, the co-metals increased the selectivity towards 1,2-propanediol, up to 96% (Ba). The co-metals inhibited sintering and stabilized the Cu particle size during reaction, by decreasing the particle growth by a factor of 10. Overall, co-metals mainly influenced the selectivity and stabilized the Cu particle.