Real‐space observation of strong metal‐support interaction: state‐of‐the‐art and what's the next

Abstract

The real-space resolving of the encapsulated overlayer in the well-known model and industry catalysts, ascribed to the advent of dedicated transmission electron microscopy, enables us to probe novel nano/micro architecture chemistry for better application, revisiting our understanding of this key issue in heterogeneous catalysis. In this review, we summarize the latest progress of real-space observation of SMSI in several well-known systems mainly covered from the metal catalysts (mostly Pt) supported by the TiO2 , CeO2 and Fe3 O4 . As a comparison with the model catalyst Pt/Fe3 O4 , the industrial catalyst Cu/ZnO is also listed, followed with the suggested ongoing directions in the field.

The Stability Challenges of Oxygen Evolving Catalysts: Towards a Common Fundamental Understanding and Mitigation of Catalyst Degradation

“…Ap artially covering oxide overlayer has been observed for Pt supported on TiO 2 . [91] It is possible that similar effects may exist for OER catalysts,asthe stability on ATOi ss ignificantly increased when the catalyst is synthesized with the support instead of ap ost-synthesis deposition. Plessow et al calculated the adsorption energy of metal atoms (e.g.…”

“…The observed interactions are termed MMOSIs (metal/metaloxide support interactions) and are used to explain the Figure 9. Strong metal-support interactions; [91] Reprinted with permission from Wiley.…”

Integrating Catalysis of Methane Decomposition and Electrocatalytic Hydrogen Evolution with Ni/CeO2 for Improved Hydrogen Production Efficiency

“…[19] This suggests that the valence state of Ni in Ni/CeO 2 has slightly increased, which may be attributed to the MSI between Ni and CeO 2 ,t hat is, in this case, some oxygen atoms are transported from CeO 2 to the surface of Ni, subsequently restraining the movement of Ni NPs (Figure 1, step Ic atalysts). [20] The first nearest neighbor shell at 2.12 and the other NiÀNi peaks in Ni/CeO 2 are shorter than the corresponding interatomic distances in Ni* (Figure 2b), which suggestst hat the NiÀNi bonds were compressed in Ni/ CeO 2 .T his may be attributedt ot he dispersive Ni NP distribution in CeO 2 .…”

“…That there is no match between the interatomic distance of Ni*o rN i/CeO 2 with NiO indicates that the Ni state is metallic,a nd not oxidized, in Ni* and Ni/CeO 2 .I ti ss ignificant, however, that the adsorption Ke dge in Ni/CeO 2 has been slightly shifted towardsahigher energy,i nc omparison to that of Ni*. [20] The first nearest neighbor shell at 2.12 and the other NiÀNi peaks in Ni/CeO 2 are shorter than the corresponding interatomic distances in Ni* (Figure 2b), which suggestst hat the NiÀNi bonds were compressed in Ni/ CeO 2 .T his may be attributedt ot he dispersive Ni NP distribution in CeO 2 . [19] This suggests that the valence state of Ni in Ni/CeO 2 has slightly increased, which may be attributed to the MSI between Ni and CeO 2 ,t hat is, in this case, some oxygen atoms are transported from CeO 2 to the surface of Ni, subsequently restraining the movement of Ni NPs ( Figure 1, step Ic atalysts).…”

“…Twoc learp eaks of hydrogen consumptiona re present.T he peak between 50 and 250 8Ci sa ttributed to the reducibility of adsorbed oxygen. [6a] The peak of Ni/CeO 2 shiftingt ol ower temperaturei sm ainly causedb yo xygen in NiO stemming from CeO 2 (owing to the MSI), [20] which can be easily reduced by H 2 . The NiÀCeÀOs olid solutionb etween the interface of Ni and CeO 2 NPs is one kind of MSI.…”