Efficient catalytic hydrogen generation by intermetallic platinum-lead nanostructures with highly tunable porous feature

The water-gas shift (WGS) reaction is an essential industrial reaction for upgrading hydrogen (H₂) by removing carbon monoxide (CO), while highly efficient platinum (Pt)-based catalysts for WGS with simultaneously high activity and stability are still yet to be developed due to the poisoning issue during the reaction. Herein, we report on the porous PtPb peanut nanocrystals (porous PtPb PNCs) and porous PtPb octahedron nanocrystals (porous PtPb ONCs) with controllable ratios of Pt/Pb as extremely active and stable catalysts towards WGS reaction. It exhibits the composition-dependent activity with porous PtPb PNCs-40/ZnO being the most active for WGS to H₂, 16.9 times higher than that of the commercial Pt/C. The porous PtPb PNCs-40/ZnO also display outstanding durability with barely activity decay and negligible structure and composition changes after ten successive reaction cycles. X-ray photoelectron spectroscopy (XPS) results reveal that the suitable binding energy of Pt 4f_7/2 and the high ratio of Pt(0) to Pt(II) in porous PtPb PNCs/ZnO and porous PtPb ONCs/ZnO are crucial for the enhanced WGS activity. The CO stripping results indicate the optimized CO adsorption strength on the Pt surface ensure the excellent WGS activity and the outstanding durability. The present work demonstrates an important advance in tuning the porous metal nanomaterials as highly efficient and durable catalysts for catalysis, energy conversion and beyond.