Hydrogen-free carbon monoxide production through decomposition of formic acid over a HPW/TiO2 catalyst

Abstract

The dehydration of formic acid over supported phosphotungstic acid (H3PW12O40, HPW) catalysts was investigated for the production of hydrogen-free carbon monoxide (CO). The variations in the support type (SiO2, Al2O3, ZrO2, and TiO2) and HPW content (0.0-20.0 wt.%) affect the acidity of catalysts, which was demonstrated by the temperature-programed desorption of iso-propanol (IPA-TPD) and pyridineadsorbed infrared spectroscopy (Py-IR). The catalytic activity in formic acid dehydration exhibited a volcano-type distribution in accordance with the HPW content and was maximized at 15 wt.% loading. Furthermore, the catalytic activity was more closely related to the density of Bronsted acids than that of Lewis acids and inversely proportional to the peak temperature of propylene desorption during IPATPD. The strongly adsorbed H2O on the catalysts, which is generated during formic acid dehydration, induces deactivation of the catalyst, particularly at lower reaction temperatures (<230 degrees C). (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.