Catalytic Gasification of Lignin with Water as Oxidant: Impact of Catalyst Design, Molecular Simulations, and Inherent Safety

Lignin, the most abundant renewable source of aromatics in nature, represents a critical feedstock for sustainable energy and chemical production. Catalytic gasification with water as an oxidant can be a promising strategy for lignin valorization, enabling its conversion to hydrogen-rich syngas with improved selectivity and catalyst stability, while incorporating inherent design features that reduce deactivation and mitigate risk-prone conditions. This review highlights recent advances in catalytic systems for water-mediated lignin gasification, particularly nickel-based catalysts, zeolite supports, and core–shell materials. It also discusses their role in improving gas yields, catalyst stability, and product selectivity. Key deactivation mechanisms, such as coking and sintering, are examined alongside strategies to mitigate them. Emerging Safe-by-Design strategies for catalyst development are also discussed, with computational tools used to screen materials for coke resistance, surface reactivity, and operational robustness. Furthermore, the growing role of first-principles computational methods to unravel reaction mechanisms and guide rational catalyst design is highlighted. This review outlines the current state of the field, identifies key gaps, and proposes future directions, especially the integration of molecular-level modeling and safety-aware catalyst design as mutually reinforcing goals for sustainable lignin valorization.