Dynamic structural evolution of 2D/3D MoS2@Ni heterostructure supported on SBA-15 during CO2 RWGS reaction

Abstract

Two-dimensional (2D) layered materials have attracted significant interest for catalytic applications due to tuneable electronic properties, and a high density of edge-active sites associated to a high proportion of reactant-accessible active sites. In this work, we report the synthesis of 2D/3D MoS₂@Ni/SBA-15 heterostructure via thermal in situ gas-phase sulfidation of MoO₃@NiO/SBA-15 precursor, aimed at promoting reverse water–gas shift (RWGS) reaction. Catalytic tests, conducted over a wide temperature range (200–800 °C) revealed that the MoS₂@Ni/SBA-15 catalyst significantly outperforms its oxidic counterpart in terms of product selectivity, while both catalysts exhibit high CO₂ conversion. Notably, the sulfided heterostructure achieves complete suppression of CH₄ formation and maintains 100% selectivity towards CO across the entire temperature range studied. In contrast, MoO₃@NiO/SBA-15 favours methanation at low temperatures and only shifts to CO production at T > 600 °C. At 500 °C, a CO₂ conversion of 33.3% is achieved on MoS₂@Ni/SBA-15 with exclusive CO selectivity, surpassing most state-of-the-art transition metal-based catalysts operating at similar conditions. Moreover, long-term stability tests at 800 °C, over 100 h, confirmed its remarkable stability, maintaining high CO₂ conversion (>75%) and full CO selectivity without any visible deactivation. These results demonstrate the strong potential of engineered 2D/3D MoS₂-based heterostructures as efficient, robust, and non-noble metal catalysts for sustainable CO₂ valorisation.