Tackling irreversible catalyst deactivation: knowledge-driven design and operation of dynamic responsive methanation catalysts

该项目的总体目标是对瞬态和潜在失活条件下的甲烷化反应进行全面、基本但数学上可管理的描述，同时考虑到催化剂的强制变化。这一目标是追求两种不同的催化剂系统，SPP的工业甲烷化参考催化剂（IMRC）和一种新的动态响应甲烷化（DRM）催化剂，它具有克服传统的镍基CO2甲烷化催化剂的不可逆失活的潜力。因此，本项目结合了尖晶石基DRM催化剂的合成、表征和探索。通过优化材料的还原性，本项目开发的DRM催化剂通过活性Ni颗粒的形成和再结合来响应外部施加的强制变化。SPP的Ni/Al 2 O3基IMRC的第一阶段资金中获得的方法和结果将在第二阶段扩展到DRM催化剂。为此，两个专用的实验装置的空间分辨DRIFTS（SRD）operando分析吸附在催化剂表面上的物种，以及一个专用的动力学设置（KIN反应器）从第一阶段被用来验证和探索动态模型，考虑在瞬态反应条件下的活性位点（失活或活化）的变化。一种新型的DRM催化剂将在催化性能（PER）测试反应器中合成和催化研究，该反应器允许通过快速改变所应用的气体混合物来实现高度瞬态的反应条件。通过在该联合体内以及与其他SPP 2080联合体合作的非原位、原位和操作方法对理想DRM催化剂进行彻底表征，允许建立固态动力学模型，该模型可以集成到反应动力学模型中。通过这种方式，建立了不同复杂性的动力学模型，包括稳态动力学模型，后者的扩展，包括描述催化剂失活和再生的机制，以及考虑表面覆盖率的动态动力学模型，用于描述瞬态条件下的反应。在此模型基础上，将开发优化方法，揭示最佳操作策略，以实现高甲烷产率和长期催化剂操作。该项目联盟内专家的密切合作涵盖了“操作/光谱”（A），“动力学建模”（C），“目标材料设计”（D）和“反应器概念”（E）不仅有助于描述和理解动态操作下的催化剂，而且有助于一种利用不希望的瞬变以提高催化剂的长期性能的新方法。

The general objective of this project is to enable a holistic, fundamental yet mathematically manageable description of the methanation reaction under transient and potentially deactivating conditions taking forced changes of the catalyst into account. This objective is pursued for two different catalyst systems, the SPP’s industrial methanation reference catalyst (IMRC) and a novel dynamic responsive methanation (DRM) catalyst which holds potential to overcome irreversible deactivation of conventional Ni-based CO2 methanation catalysts. Therefore, this project combines synthesis, characterization and exploration of a spinel based DRM catalyst. Enabled by optimized reducibility of the material, the DRM catalyst developed in this project responds to externally applied forced changes by formation and reintegration of active Ni particles.Methods and results obtained in funding phase I for the SPP’s Ni/Al2O3 based IMRC will be extended for the DRM catalyst in phase II. For this, two dedicated experimental set-ups for spatially-resolved DRIFTS (SRD) operando analysis of species adsorbed on the catalyst surfaces as well as a dedicated kinetic set-up (KIN reactor) from phase I are utilized to validate and explore dynamic models that consider the change of active sites (deactivating or activating) during transient reaction conditions. A novel DRM catalyst will be synthetized and catalytically investigated in a catalytic performance (PER) test reactor which allows for the realization of highly transient reaction conditions by fast changes of applied gas mixtures. A thorough characterization of an ideal DRM catalyst by ex situ, in situ and operando methods within this consortium and in cooperation with further SPP2080 consortia allows to establish a solid state kinetic model, which can be integrated into the reaction kinetic model. This way, kinetic models of different complexity are established, including steady-state kinetic models, extensions of the latter for including mechanisms to describe catalyst deactivation and regeneration as well as dynamic kinetic models considering surface coverages for describing the reaction under transient conditions. On this model basis, optimization methods will be developed that reveal optimal operation policies to enable both, high methane yields and long term catalyst operation.The close collaboration of experts within this project consortium covering the areas “operando/spectroscopy” (A), ”kinetic modelling” (C), ”targeted material design” (D) and ”reactor concepts” (E) not only contributes to the description and understanding of catalysts under dynamic operation, but also contributes to a novel approach to exploit unwanted transients to enable enhanced long term performance of catalysts.