544628 Indium Oxide As Promoter in Cu/ZrO2 Catalysts for CO2 hydrogenation to Methanol

Wednesday, June 5, 2019
Texas Ballroom Prefunction Area (Grand Hyatt San Antonio)
Marco A. Rossi Sr.1, José M. Assaf2 and Elisabete M. Assaf1, (1)Instituto de Química de São Carlos/Universidade de São Paulo, São Carlos, Brazil, (2)Universidade Federal de São Carlos, Engenharia Química, Brazil

Indium oxide as promoter in Cu/ZrO2 catalysts for CO2 hydrogenation to methanol.

Rossi, M.A.1; Assaf, J. M2; Assaf, E.M.1

1 University of São Paulo, São Carlos Institute of Chemistry. Av. Trabalhador São Carlense, 400, 13560-970, São Carlos, SP, Brazil. eassaf@iqsc.usp.br

2 Federal University of São Carlos, Rod. W. Luiz, km 235, 13565-905, São Carlos, SP, Brazil.

The importance of strategies for the capture and utilization of CO2, that can be found as constituent in biogas and natural gas, is increasing significantly in global context. Among these strategies, the catalytic process of carbon dioxide hydrogenation is one of the most promising with the aim to obtain products with higher added value such as methanol.

The catalysts used in this process are generally based on metallic copper supported on oxides such as zirconia and alumina. Recent theoretical studies have shown the potential of pure indium oxide to obtain methanol with high selectivity, but it was not tested as promoter on catalysts based on copper until the moment.

The objective of this work was to investigate the influence of different molar contents of indium oxide as promoter on catalysts based on metallic copper and zirconia.

Cu/ZrO2 catalysts without promoter and with 5% and 10% of indium oxide, in molar content, were synthesized by the co-precipitation method at constant pH assisted by the CTAB surfactant, followed by calcination in air. The synthesized materials were characterized by thermogravimetry, ex-situ and in-situ X ray diffraction, energy dispersive x ray spectroscopy, temperature programmed reduction, CO2 temperature programmed desorption, transmission electron microscopy and N2 sorption measurements using the BET model.

The catalytic tests were performed in a continuous flow tubular fix-bed PID Microactivity Effi reactor under pressure of 3 MPa, temperature of 250°C and GHSV of 6 L.g-1.h-1.

The results allowed to verify that the addition of indium oxide, even in the lowest content, increased the selectivity to methanol from 40% to 55% with decrease in the selectivity for other products such as CO, due to the fact that indium oxide improve the occurrence of the reaction mechanism by the formate route, being this, the most effective pathway to generate methanol with high selectivity.

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