Anton Radulescu*, S. Iravani

ABSTRACT

: The global chemical industry is undergoing a profound transformation driven by the urgent need to achieve sustainability without compromising industrial productivity. Conventional chemical synthesis routes are increasingly scrutinized due to their reliance on hazardous reagents, high energy consumption, and significant waste generation. In this context, metal oxide nanocatalysts have emerged as promising materials due to their high surface area, tunable physicochemical properties, and superior catalytic performance. However, traditional synthesis methods for nanocatalysts often contradict the principles of green chemistry. This review critically examines recent advances in the green synthesis of metal oxide nanocatalysts using eco-friendly precursors, biological resources, and low-energy processes. Emphasis is placed on synthesis strategies, structure–property relationships, catalytic applications, and environmental benefits. The challenges associated with scalability, reproducibility, and industrial implementation are discussed, and future research directions are proposed to accelerate the transition toward sustainable catalytic technologies. Keywords: Green chemistry; Metal oxide nanocatalysts; Sustainable catalysis; Eco-friendly synthesis; Heterogeneous catalysis; Environmental remediation; non-renewable resources; pharmaceuticals, energy; agriculture; manufacturing; toxic waste generation