Precise Modulation of Triple-Phase Boundaries towards a Highly Functional Exsolved Catalyst for Dry Reforming of Methane under a Dilution-Free System.

Dry reforming of methane (DRM) has been emerging as a viable solution to achieving carbon neutrality enhanced by the Paris Agreement as it converts the greenhouse gases of CO 2 and CH 4 into industrially useful syngas. However, there have been limited studies on the DRM catalyst under mild operating conditions with a high dilution gas ratio due to their deactivation from carbon coking and metal sintering. Herein, we apply the triple-phase boundary (TPB) concept to DRM catalyst via exsolution phenomenon that can secure elongated TPB by controlling the Fe-doping ratio in perovskite oxide. Remarkably, the exsolved catalyst with prolongated TPB shows exceptional CO 2 and CH 4 conversion rates of 95.9 % and 91.6 %, respectively, stable for 1000 hours under a dilution-free system. DFT calculations confirm that the Lewis acid of support and Lewis base of metal at the TPB promote the adsorption of reactants, resulting in lowering the overall CO 2 dissociation and CH 4 dehydrogenation energy.