Abstract
Abstract
Lactic acid (LA) is a versatile platform chemical widely used in food, pharmaceutical, and biodegradable plastic industries. While industrial LA production predominantly relies on fermentation, the chemo-catalytic conversion of renewable biomass-especially non-edible lignocellulosic feedstocks-has emerged as a promising alternative due to its potential for higher efficiency, lower environmental impact, and reduced competition with food resources. This review systematically summarizes recent advances in the chemo-catalytic production of lactic acid from biomass-derived sugars, glycerol, and real biomass (e.g., cellulose, straw). The catalytic systems are categorized into three main types: alkaline catalysis (including homogeneous and heterogeneous bases), acid catalysis (focusing on Lewis acid zeolites, metal oxides, and rare-earth catalysts), and emerging photocatalytic approaches. Key reaction pathways, catalyst design strategies, and the roles of active sites are discussed in detail. A comparative analysis of catalytic performance under various conditions is presented, along with a critical evaluation of challenges such as catalyst stability, product separation, and scalability. Finally, future directions for the development of sustainable and industrially viable LA production processes are proposed.