Gold nanocatalysts supported on Mono-/Mixed oxides for efficient synthesis of methyl methacrylate

Abstract

Developing sustainable methods for producing methyl methacrylate (MMA) has gained strategic importance for industrial applications and as a promising oxygenated fuel additive to enhance combustion efficiency and reduce emissions. This dual-purpose approach addresses both industrial needs and the growing demand for cleaner fuel solutions. Our study focuses on synthesizing gold nanoparticles (AuNPs) supported by alumina (Al₂O₃), cerium oxide (CeO₂), and Al₂O₃/CeO₂ combination by deposition–-precipitation method, aiming to advance far-reaching MMA synthesis through direct oxidative esterification (DOE) of methacrolein (MAL) with methanol. The research explores the relationship between catalyst structure and activity, particularly investigating the impact of AuNPs doping on Al₂O₃, CeO₂, and Al₂O₃/CeO₂ and the mechanism that promotes selective oxidation. The intimate interaction between CeO₂ and Al₂O₃ and adequate doping of AuNPs with Al₂O₃/CeO₂ is beneficial in enhancing catalytic activity and facilitating selective oxidation. Notably, Au/Al₂O₃/CeO₂ demonstrated significantly higher catalytic activity compared to Au/Al₂O₃ and Au/CeO₂ catalysts, achieving 98% MAL conversion and 95% MMA selectivity. The reaction yield, in particular, strongly correlated with surface and active oxygen species around AuNPs. This highly efficient catalytic process provides a green route for MMA production and enables its application as a sustainable fuel additive, contributing to improved engine performance and reduced environmental impact. The optimized catalyst system presents a viable pathway for both industrial chemical production and sustainable energy applications, addressing crucial environmental and energy challenges simultaneously.