Estudo de diferentes suportes catalíticos para a reação de reverse water gas shift (RWGS)

Abstract

Given the increasing impacts of climate change, reducing greenhouse gas emissions has become a global priority. A promising strategy to mitigate the environmental effects of carbon dioxide (CO₂) is its conversion into value-added products, reducing dependence on fossil fuel derivatives. In this context, the Reverse Water Gas Shift (RWGS) reaction emerges as a viable alternative to transform CO₂ into carbon monoxide (CO), a crucial intermediate in the production of chemicals and synthetic fuels. One of the main challenges of this process is the development of efficient and selective catalysts for CO₂ conversion. This study aimed to synthesize and evaluate copper-based catalysts supported on sodium titanate nanotubes (TNT) and zeolites of the MCM-22, X, and Y types. The titanate nanotubes were obtained through the hydrothermal method, as well as the zeolites, and subsequently impregnated with 10% copper using a copper nitrate solution. The catalysts were tested in the RWGS reaction at temperatures ranging from 450 to 700 ºC in a continuous fixed-bed reactor with a gas hourly space velocity (GHSV) of 15000 mL h⁻¹ g⁻¹. The results showed high selectivity for CO, exceeding 90%, and CO₂ conversion of up to 60%, depending on the catalyst used. Among the supports developed from rice husk, the copper-impregnated MCM-22 zeolite exhibited the best performance, standing out as a promising material for catalytic CO₂ conversion.