Beyond metals: Tailored metal-free boron-oxy-carbide catalysts for CO2 hydrogenation

The rational design of functional materials through targeted element-selection strategies offers a promising route for developing next-generation catalysts. Here, we employ this strategy to tackle critical challenges in the Reverse Water Gas Shift (RWGS) reaction, including catalyst deactivation, low CO selectivity, and the high cost of conventional transition-metal catalysts. Through this approach, we designed and synthesized a novel class of metal-free boron-oxy-carbide (BO) catalysts. The catalyst exhibited 100% CO selectivity and maintained equilibrium CO₂ conversion without deactivation for over 250 hours at 600 °C. Advanced characterization techniques, combined with density functional theory (DFT) calculations suggested that the ‘B-O-C triad’ within the BO lattice is responsible for the RWGS activity. These findings demonstrate the potential of BO catalysts as robust, scalable, and sustainable alternatives to state-of-the-art transition-metal-based catalysts for CO₂ valorization. We anticipate that these findings will provide a foundation for the design and activity of metal-free catalysts applicable to a diverse range of chemical transformations. Metal free boron-oxy-carbide catalysts designed via strategical elemental screening for reverse water gas shift (RWGS) reaction. • Metal-free boron-oxy-carbide (BO) catalysts designed via targeted element selection. • BO catalysts show 100% CO selectivity in the RWGS reaction at 600 °C. • Stable CO2 conversion without deactivation for over 250 hours. • ‘B-O-C triad’ identified as the active site by advanced characterization and DFT. • Metal-free BO catalysts offer a scalable, sustainable alternative to transition metals.