钙钛矿的自再生效应及其对镍基甲烷干重整催化剂性能的增强作用

Ni-based catalysts are widely used in CH4 conversions, however they suffer from serious coking and sintering degeneration problems. In the present project, we target at exploring thermal stable Ni-based catalysts with high activity and good anti-coking properties by using dry reforming of methane as a model reaction. We will focus on the self-regeneration effect of perovskites (ABO3) and its influences on the catalytic processes. We propose a new idea on self-regeneration effect that it happen not only on the B-site element, but also on the A-site element of an ABO3 host material. We will study the key factors and mechanisms of self-regeneration by tailoring the composition, microstructure and electronic structure of ABO3 through A- and B-sites doping, and by observing influences of experimental conditions, such as reaction temperature and partial oxygen pressure, on the self-regeneration effects of both A- and B-site elements. Further, we will try to promote synergetic catalysis from different components in the multi-phase catalyst by via self-regeneration effect. It is expected that highly active thermal stable Ni-based catalysts with good anti-coking properties will be obtained. Research findings of this project will also be valuable for other research areas of catalysis.

Ni基催化剂在甲烷的转化等领域有重要的应用背景，但存在着严重的积碳和烧结退化问题。在本项目中，我们以甲烷干重整反应为模型反应，以获得高活性、抗积碳和热稳定的Ni基催化剂为目标，重点研究钙钛矿（ABO3）材料的自再生效应及其对催化过程的影响。本项目提出以ABO3宿主材料为媒介不仅能引发B位元素的自再生效应，还能引发A位元素的自再生效应这一全新的概念。我们将主要通过A/B位的掺杂调控ABO3的成分、微结构和电子结构，同时考察温度和氧分压等实验条件对A/B位元素自再生效应的影响，探索自再生效应的关键影响因素和机理。在此基础上，我们还将利用自再生效应促进多相复合材料各组分之间的协同催化，以期增强Ni基催化剂的活性、抗积碳性和热稳定性，获得高性能的催化剂材料。本项目预期的研究成果对其它催化领域也将有重要的参考价值。

Ni基催化剂在甲烷的转化等领域有重要的应用背景，但存在着严重的积碳和烧结退化问题。在本项目执行过程中，我们通过设计和掺杂合成了系列的Ni基钙钛矿催化剂材料，调控了催化剂的表面和界面、成分、微结构和电子结构，研究了自再生效应的关键影响因素和物理机制，发现钙钛矿材料的缺陷、离子间的相互作用强度、活性离子的化学态是影响催化剂活性金属分散度、活性、抗积碳性和热稳定性的关键影响因素。在此基础上，课题组设计并合成出了利用结构稳定钙钛矿载体表面晶格锚定的活性钙钛矿亚单层催化剂材料，这种催化剂的活性金属镶嵌于钙钛矿亚单层的晶格中，呈原子级分散，处于低价氧化态，对DRM反应具有接近热力学平衡的高催化活性、高抗积碳性能和热稳定性。本项目提出的钙钛矿亚单层催化剂是一种不同于金属-载体催化剂和单原子催化剂的新型催化剂，所提出的催化剂设计理念和调控方法对设计新型催化剂具有重要的启发和参考价值。