Decoding\nthe Promotional Effect of Iron in Bimetallic\nPt–Fe-nanoparticles on the Low Temperature Reverse Water–Gas\nShift Reaction

The\nreverse water–gas shift (RWGS) reaction is a key technology\nof the chemical industry, central to the emerging circular carbon\neconomy. Pt-based catalysts have previously been shown to effectively\npromote RWGS, especially when modified by promoter elements. However,\ntheir active states are still poorly understood. Here, we show that\nthe intimate incorporation of an iron promoter into metal-oxide-supported\nPt-based nanoparticles can increase their activity and selectivity\nfor the low temperature reverse water–gas shift (LT-RWGS) substantially\nand drastically outperform unpromoted Pt-based materials. Specifically,\nthe study explores the promotional effect of iron in Pt–Fe\nbimetallic systems supported on silica (Pt<sub><i>x</i></sub>Fe<sub><i>y</i></sub>@SiO<sub>2</sub>) prepared by surface\norganometallic chemistry (SOMC). The most active catalyst (Pt<sub>1</sub>Fe<sub>1</sub>@SiO<sub>2</sub>) shows high selectivity (>99%\nCO) toward CO at a formation rate of 0.192 mol<sub>CO</sub> h<sup>–1</sup> g<sub>cat</sub><sup>–1</sup>, which is significantly\nhigher than that of monometallic Pt@SiO<sub>2</sub> (96% sel. and\n0.022 mol<sub>CO</sub> h<sup>–1</sup> g<sub>cat</sub><sup>–1</sup>). In-situ diffuse reflectance FT-IR spectroscopy (DRIFTS) and X-ray\nabsorption spectroscopy (XAS) indicate a dynamic process at the catalyst\nsurface under the reaction conditions, revealing distinct reaction\npathways for the monometallic Pt@SiO<sub>2</sub> and bimetallic Pt<sub><i>x</i></sub>Fe<sub><i>y</i></sub>@SiO<sub>2</sub> systems.