Effective integration of CO₂ capture and its conversion is an attractive strategy to reduce the anthropogenic CO₂ emissions meanwhile achieve the potential revenue of CO₂ molecule. Calcium-looping dry reforming of methane (CaLDRM) has emerged as such a promising process, implemented over a bifunctional reactor combining a CaO-based sorbent and a Ni-based catalyst, to achieve CO₂ capture and in-situ conversion with CH₄ into syngas. Herein, we synthesize a bifunctional Ni-Ca based material, i.e. Ni and CeO₂ nanoparticles co-loaded on ZrO₂-coated CaCO₃, which enables isothermal capture and release of CO₂ at the temperature favorable for DRM reaction, allowing to operate CaLDRM process in a single reactor by simple gas switching. Thanks to the stabilization effect of the ZrO₂ layer, both CaO and Ni particles are exempted from severe sintering, maintaining the activity of capture and catalysis. The addition of CeO₂ contributes not only to combat the accumulation of inactive carbon during long-term DRM but also to activate CO₂ and CH₄, accordingly enhancing syngas production, during cyclic CaLDRM. Importantly, the bifunctional material can succesfully drive CaLDRM cycles, converting over 40 % of CH₄ and CO₂, under 5 vol% CO₂ feed concentration (as low as real flue gas) at 720 °C, which is a thermodynamically extremely unfavorable condition (equilibrium conversion below 3 %).

有效整合CO ₂捕集及其转化是减少人为的CO ₂排放并同时实现潜在的CO ₂分子收益的有吸引力的策略。钙循环干重整甲烷（CaLDRM）已经成为这样的有前途的方法，用双官能反应器组合CaO系吸附剂和基于Ni的催化剂来实现，以实现CO ₂捕获和原位转化用CH ₄进合成气。在本文中，我们合成了双功能Ni-Ca基材料，即Ni和CeO ₂纳米颗粒共负载在ZrO ₂涂层的CaCO _3上，从而能够等温捕获和释放CO ₂在适合DRM反应的温度下，通过简单的气体切换即可在单个反应器中运行CaLDRM工艺。由于ZrO ₂层的稳定作用，CaO和Ni颗粒均免于严重烧结，从而保持了捕获和催化的活性。CeO ₂的添加不仅有助于在长期DRM过程中对抗惰性碳的积累，而且还有助于在循环CaLDRM过程中活化CO ₂和CH ₄，从而提高合成气的产量。重要的是，双功能材料可以成功地驱动CaLDRM循环，在5 vol％的CO ₂下转化超过40％的CH ₄和CO ₂。 进料浓度（低至实际烟气）在720°C，这在热力学上是非常不利的条件（平衡转化率低于3％）。