A comparative study of the properties and hydrogenolysis activity of catalysts derived from single-phase CuZn precursors was carried out to elucidate the effect of the precursor structure on the catalyst activity in hydrogenolysis and to examine their potential to replace the classical CuCr catalysts. Three CuZn catalysts were prepared by co-precipitation aiming at Cu/Zn ratios of 0.7, 5.0 and 1.6 to obtain single-phase aurichalcite, zincian malachite and a mixture of both phases, respectively. The catalyst precursors were calcined at temperatures of 300 and 450 °C, reduced in situ and tested in dimethyl adipate hydrogenolysis. The properties of the precursors and catalysts were analyzed using in situ XRD, TGA-MS, TPR-H₂, nitrogen physisorption and N₂O chemisorption methods. According to the characterization data, aurichalcite-derived catalysts had superior structural properties to zincian malachite-derived catalysts: smaller copper crystallites, larger total and copper surface areas, and stable surface areas during the experiment. Consequently, aurichalcite-derived catalysts outperformed catalysts prepared from zincian malachite in the studied range of phase and elemental CuZn compositions. Nonetheless, the calculated intrinsic hydrogenolysis activity of surface Cu sites (TOF) was similar for all three catalysts.

CuZn catalysts are perspective catalysts for esters hydrogenolysis, but more knowledge is needed to optimize their catalytic performance. In this work, we consider the impact of CuZn catalysts composition on their structure, activity, selectivity, and stability in esters hydrogenolysis. Four catalysts with various Cu/Zn ratio were synthesized by a co-precipitation and characterized in as-prepared, calcined, reduced, and spent state by XRF, XRD, N₂ physisorption, CO₂-TPD, NH₃-TPD, and N₂O chemisorption. XRD data revealed the effect of the composition on the size of Cu and ZnO particles. The catalytic performance was investigated using an autoclave. All catalysts exhibited high methyl hexanoate conversion about 48–60% after 3 h but their activity and selectivity were found to be dependent on Cu/Zn ratio. The conversion of methyl hexanoate and hexyl hexanoate was compared to explain the observed product selectivity. Moreover, the catalysts stability was investigated in three consecutive reaction cycles and correlated with changes in the size of constituent particles. Moreover, when different esters were tested, a slight decrease in conversion and increase in alcohol selectivity with a growth in molecule size was observed. Obtained results allow making a conclusion about the optimal composition that provides the good performance of CuZn catalysts in ester hydrogenolysis.