Positive cooperativity of CaSiO3 and platinum-tin catalyst in reaction of acetic acid to ethanol

Catalytic hydrogenation of acetic acid to ethanol was investigated in a fixed-bed micro-reactor with calcium silicate-modified platinum-tin catalyst at mild reaction condition. The modified catalyst exhibited excellent performance for the ethanol synthesis process at relatively low pressure. According to the results of H 2 -pulse chemisorption experiments, the introduction of calcium silicate promoted the dispersion of platinum particles. The NH 3 -TPD and H 2 -TPR results showed the decrease of acid content on catalyst surface and the enhancement of reducibility after the CaSiO 3 modification. Additionally, the results of XPS indicated that Sn (0) was emergent and Pt (2+) was sharply decreased after reduction. Both the H 2 -TPR and XPS results supported the formation of Pt-Sn alloy during the reduction process at 623 K. The Pt-Sn alloy changed the electron density and benefited the free hydrogen dissociation and hydrogenation. The enhancement of reaction temperature and pressure both promoted acetic acid conversion. The kinetic model of power-function type was established to describe the process of hydrogenation. The results of residual analysis confirmed that the raised kinetic model for acetic acid to ethanol reaction was suitable.