Tuning supported Fe-Ag catalysts for selective acetylene hydrogenation: A combined experimental and computational study

We report the use of Fe–Ag bimetallic nanoparticles supported on α-Al₂O₃ as tunable highly active and selective catalysts for the semihydrogenation of acetylene in ethylene rich streams. The addition of silver enhances the ethylene selectivity. Experimental evidence was supported by DFT calculations predicting Gibbs free energies and adsorption energies as a function of catalyst composition. Comprehensive characterization was carried out using ICP, XRF, XRD, N₂-physisorption, TPR, STEM-EDX, and XPS. This work is inspired by the need for more sustainable catalysts beyond Pd for the removal of trace amounts of acetylene from the ethylene under front-end conditions downstream of industrial steam crackers for olefin production. Conventional Pd-based catalysts, though highly active, suffer from limited selectivity, high cost, and environmental concerns. Iron emerges as a sustainable alternative due to its abundance, low toxicity, and favorable hydrogenation activity. Incorporation of silver into iron catalysts leverages synergistic effects that allow to tune the performance of the catalysts. These effects result in enhanced catalytic activity and improved selectivity towards ethylene. The present work demonstrates a promising approach for developing cost-effective, sustainable, and highly active catalysts for industrial acetylene hydrogenation.