CO2 Hydrogenation Over K‐Promoted Fe‐Catalysts Derived from Mg–Al–Fe Quintinite‐Like Layered Double Hydroxide Precursor

作者：R. Rabelo-Neto, Ana Paula da Silva Grangeiro, R. Simões, M. K. Gnanamani, M. Martinelli, Dali Qian, Fabio Bellot Noronha, Gary Jacobs · 发表于：ChemCatChem · 年份：2025 · DOI：10.1002/cctc.202500935 · 被引用次数：3

This work investigates the performance of iron‐based catalysts for CO2 hydrogenation, whereby the iron‐carbide active phase is derived from a high surface area Mg–Al–Fe quintinite‐like layered double hydroxides precursor. CO2 temperature‐programmed desorption experiments on calcined and carburized materials demonstrate that K addition increases surface basicity, promoting CO2 adsorption. CO temperature‐programmed reduction and HR‐TEM/EDS experiments reveal that adding K facilitates CO dissociation, altering the surface carbon/hydrogen pool. Both H2‐TPR and reverse water–gas shift tests at 1 atm show that K addition suppresses H‐transfer. The highest yield of CO and the lowest yield of CH4 from RWGS occur for the carburized catalyst having a K‐promoter. Adding K improves the product distribution for both Fischer–Tropsch synthesis and CO2 hydrogenation. For FTS, adding K decreases methane selectivity (from 14% to 4.4%) and increases C5+ selectivity (from 38% to 51.1%). For CO2 hydrogenation, adding K decreases CH4 selectivity from 40%–50% to 19.0% and increases C5+ selectivity from 0–8% to 37.9%, and the catalyst performs significantly better than a typical precipitated Fe FTS catalyst. At a conversion two times higher than a related CuFe8‐LDO catalyst reported recently, the C5+ selectivity was ∼4 times higher. The C5+ selectivity results are also comparable to a recently reported ZnAlFe‐LDH catalyst.