Preparation of highly dispersed Cu catalysts from hydrotalcite precursor for the dehydrogenation of 1,4-butanediol

Copper-based catalysts are widely used in methanol synthesis, selective catalytic reduction of NOx, hydrogenation, dehydrogenation and hydrogenolysis reactions. In this work, a series of Cux/Zn3−0.5xMg3−0.5xAl2O9−x catalysts were prepared via the controlled calcination and reduction of hydrotalcite-like structured CuxZn3−0.5xMg3−0.5xAl2(OH)16CO3 precursors. The formation process of Cu2/Zn2Mg2Al2O7 from Cu2Zn2Mg2Al2(OH)16CO3 was characterized via several techniques. Characterizations results indicated that the dispersion of Cu in reduced Cu2/Zn2Mg2Al2O7 reached 79.3%, and it exhibited excellent activity for the dehydrogenation of 1,4-butanediol (1,4-BDO) to γ-butyrolactone (GBL). The detected conversion of 1,4-BDO reached 99.2% with a 99.5% selectivity of GBL at 240 °C, 0.1 MPa and LHSV−1 = 0.13 h, and the calculated productivity of GBL was 7.07 g-GBL/g-cat/h. And Cu2/Zn2Mg2Al2O7 could maintain its activity within 50 h on stream.