Penner Simon, Kheyrollahi Nezhad Parastoo Delir
Department of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria.
Reactor and Catalyst Research Lab, Department of Chemical Engineering, University of Tabriz, Tabriz, Iran.
ACS Catal. 2021 May 7;11(9):5271-5286. doi: 10.1021/acscatal.1c00718. Epub 2021 Apr 16.
Based on the increasing importance of intermetallic compounds and alloys in heterogeneous catalysis, we explore the possibilities of using selected intermetallic compounds and alloy structures and phases as catalyst precursors to prepare highly active and CO-selective methanol steam reforming (MSR) as well as dry reforming of methane (DRM) catalyst entities by controlled decomposition and self-activation. The exemplary discussed examples (CuZr, CuZn, PdZr, GaPd, CuIn, ZnPd, and InPd) show both the advantages and pitfalls of this approach and how the concept can be generalized to encompass a wider set of intermetallic compounds and alloy structures. Despite the common feature of all systems being the more or less pronounced decomposition of the intermetallic compound surface and bulk structure and the formation of much more complex catalyst entities, differences arise due to the oxidation propensity and general thermodynamic stability of the chosen intermetallic compound/alloy and their constituents. The metastability and intrinsic reactivity of the evolving oxide polymorph introduced upon decomposition and the surface and bulk reactivity of carbon, governed by the nature of the metal/intermetallic compound-oxide interfacial sites, are of equal importance. Structural and chemical rearrangements, dictating the catalytic performance of the resulting entity, are present in the form of a complete destruction of the intermetallic compound bulk structure (CuZr) and the formation of an metal/oxide (CuZr, InPd) or intermetallic compound/oxide (ZnPd, CuIn, CuZn) interface or the intertranformation of intermetallic compounds with varying composition (PdZr) before the formation of Pd/ZrO. In this Perspective, the prerequisites to obtain a leading theme for pronounced CO selectivity and high activity will be reviewed. Special focus will be put on raising awareness of the intrinsic properties of the discussed catalyst systems that need to be controlled to obtain catalytically prospective materials. The use of model systems to bridge the material's gap in catalysis will also be highlighted for selected examples.
基于金属间化合物和合金在多相催化中日益重要的地位，我们探索了使用选定的金属间化合物以及合金结构和相作为催化剂前体的可能性，通过可控分解和自活化来制备高活性且对一氧化碳具有选择性的甲醇蒸汽重整（MSR）以及甲烷干重整（DRM）催化剂实体。所讨论的示例（CuZr、CuZn、PdZr、GaPd、CuIn、ZnPd和InPd）展示了这种方法的优点和缺陷，以及如何将该概念推广到涵盖更广泛的金属间化合物和合金结构。尽管所有体系的共同特征是金属间化合物表面和体相结构或多或少会发生明显分解，并形成更为复杂的催化剂实体，但由于所选金属间化合物/合金及其成分的氧化倾向和一般热力学稳定性的差异，仍会出现不同情况。分解时引入的演化氧化物多晶型的亚稳性和本征反应性，以及由金属/金属间化合物 - 氧化物界面位点性质所决定的碳的表面和体相反应性，同样重要。决定所得实体催化性能的结构和化学重排，表现为金属间化合物体相结构的完全破坏（CuZr）、金属/氧化物（CuZr、InPd）或金属间化合物/氧化物（ZnPd、CuIn、CuZn）界面的形成，或者在形成Pd/ZrO之前具有不同组成的金属间化合物的相互转变（PdZr）。在本综述中，将回顾获得显著一氧化碳选择性和高活性这一主导主题的先决条件。特别关注的是提高对所讨论催化剂体系本征性质的认识，这些性质需要加以控制才能获得具有催化前景的材料。还将针对选定示例强调使用模型体系来弥合催化领域材料差距的情况。
