The recently demonstrated concept to combine CO₂ capture and utilization in one process using isothermal unsteady-state operation, namely CO₂ capture and reduction (CCR), was applied for CO₂ methanation using unpromoted and K- or La-promoted Ni/ZrO₂ catalysts. Both K and La promoters significantly improve CO₂ capture capacity and also the selectivity of CO₂ conversion to methane. The K-promoted catalyst (Ni-K/ZrO₂) captures a larger amount of CO₂ at high temperature but the capture capacity drops at low temperature due to incomplete catalyst regeneration during the cyclic unsteady-state reaction condition. In contrast, the La-promoted catalyst (Ni-La/ZrO₂) shows temperature-independent CO₂ capture capacity and rapid reduction of captured CO₂, thus leading to stable CCR performance. The nature of the active sites and mechanistic details were gained by TPR, reductive CO₂-TPD and space- and time-resolved operando DRIFTS, holistically elucidating the effects of the promoters and their impacts on CCR activity.

最近展示的将等温非稳态操作在一个过程中结合CO ₂捕集和利用的概念，即CO ₂捕集和还原（CCR），被应用在使用未促进的和K或La促进的Ni / ZrO _2的CO ₂甲烷化中催化剂。K和La促进剂都显着提高了CO _2的捕集能力，也提高了CO ₂转化为甲烷的选择性。K促进的催化剂（Ni-K / ZrO ₂）捕获大量的CO ₂在高温下，但由于在循环非稳态反应条件下催化剂再生不完全，因此在低温下，捕集能力下降。相反，La促进的催化剂（Ni-La / ZrO ₂）显示出与温度无关的CO ₂捕集能力，并且捕集的CO ₂迅速还原，因此导致了稳定的CCR性能。活性位点和机制细节的性质是由TPR上涨，还原CO ₂ -TPD和空间和时间分辨operando漂移整体上阐明发起人及其对CCR活动的冲击效应。