High-entropy oxide nanosheets enable robust dry reforming of methane via synergistic exsolution and electronic modulation

Developing high-performance catalysts for dry reforming of methane (DRM) requires balancing activity, stability, and carbon resistance. Here, we reported a high-entropy oxide (HEO) nanosheet catalyst, (Mg0.4Fe0.2Co0.2Ni0.2)Al2O4, synthesized via a solvent-free citrate-assisted route, which achieved exceptional DRM performance. The HEO nanosheets exhibited outstanding activity at 750 °C, with CH4 and CO2 conversions exceeding 89% and 92%, respectively, while maintaining stability for >400 h—far surpassing sol-gel-derived counterparts (CH4/CO2 conversions 4/CO2 (−1.59 eV) compared to pure Ni (−2.42 eV) enhanced charge transfer to reactants, weakening C–H and C–O bonds. This electronic modulation, coupled with the nanosheet morphology, suppressed sintering and carbon deposition, as evidenced by negligible mass loss (98% retention) after 400 h. Raman and TEM analyses confirmed that the HEO nanosheets resisted graphitic carbon formation, unlike conventional catalysts plagued by fibrous coke. This work demonstrates how HEO-derived alloy catalysts synergize structural robustness and electronic optimization to advance DRM technology.