Recent advances in Cu-Ni-based catalysts for CO2 hydrogenation to methanol: Effects of morphology, synthesis methods, and supports

The persistent increase in atmospheric CO 2 concentration, mainly driven by continued dependence on fossil fuels, has intensified global warming and accelerated a range of associated environmental concerns. Catalytic hydrogenation of CO 2 to methanol is a promising mitigation approach, as it converts CO 2 into value-added chemicals within a sustainable energy framework. However, this reaction is limited by thermodynamic constraints, kinetic barriers, and weak CO 2 adsorption on catalysts, highlighting the need for catalysts that enhance CO 2 activation and stabilise key intermediates. In this regard, bimetallic catalysts have garnered increasing attention due to their ability to generate tunable geometrical and electronic environments that cannot be achieved with single-metal systems. In particular, the Cu-Ni combination provides a compelling platform, for which Cu is generally recognised for its activity in CO 2 activation and the formation of methanol-related intermediates. In contrast, Ni offers strong H 2 dissociation capabilities and promotes the reduction and electronic modification of Cu. When appropriately engineered through structural design, interface regulation, and controlled dispersion on suitable supports, the interaction between Cu and Ni gives rise to pronounced synergistic effects that substantially enhance catalytic performance. This review summarises recent progress in the development of Cu- and Ni-based bimetallic catalysts for methanol via CO 2 hydrogenation. Emphasis is placed on strategies for tailoring bimetallic structures, the role of support materials in modulating metal dispersion and metal–support interactions, and the influence of synthesis protocols on the physicochemical properties of the resulting catalysts. Mechanistic insights from experimental and computational studies are also discussed, with a particular focus on the role of active sites, the stabilisation of surface intermediates, and the determinants of reaction pathways. Collectively, these recent findings provide a framework for rational catalyst design and offer guidance for developing next-generation bimetallic systems with enhanced activity, improved methanol selectivity, and long-term thermal stability for sustainable CO 2 conversion.