【公開日：2025.06.10】【最終更新日：2025.05.19】

課題データ / Project Data

課題番号 / Project Issue Number

24AE0032

利用課題名 / Title

Indium-Induced Surface Reconstruction of NiO Significantly Enhances Reverse Water Gas Shift Reaction Performance

利用した実施機関 / Support Institute

日本原子力研究開発機構 / JAEA

機関外・機関内の利用 / External or Internal Use

外部利用/External Use

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）革新的なエネルギー変換を可能とするマテリアル/Materials enabling innovative energy conversion（副 / Sub）-

キーワード / Keywords

Liquid metal, Transition metal oxides, Reverse Water Gas Shift Reaction, Strong metal-support interaction

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

Wu Dongshuang

所属名 / Affiliation

Nanyang Technological University

共同利用者氏名 / Names of Collaborators Excluding Supporters in the Hub and Spoke Institutes

Yuanyuang Wang,Bing Zhu,Huayu Gu,Okkyun Seo

ARIM実施機関支援担当者 / Names of Supporters in the Hub and Spoke Institutes

松村　大樹

利用形態 / Support Type

（主 / Main）共同研究/Joint Research（副 / Sub）-

利用した主な設備 / Equipment Used in This Project

AE-006：エネルギー分散型XAFS装置

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

This experiments aims to reveal the Strong metal-support interaction (SMSI) between liquid metal nanoparticles (LM NPs) and transion metal oxides (TMO). Through our lab XRD data insitu DRFTS, we found that In NPs can extract the O from NiO even at room temperature. With increasing temperature, the In will change into In₂O₃ under Ar atomosphere and InNi₃C_0.5 under CO₂+H₂ atomoshpere, which change the reaction pathway of NiO. Our catalytic performance shows that NiO produce CH4 only and In NPs doesnot have any activity. While In/NiO showed high activity and selectivity for CO production. Such phenomenon is across multi LM-TMO systems. In this proposal, we would like to check the In K-edge and Ni/Fe K-edge change under different atomosphere with varied temperatures. 

実験 / Experimental

Prepare pellets: In, NiO, In/NiO, Fe₂O₃, In/Fe₂O₃
[1] In, Ni and Fe K-edge under Ar atmosphere in from RT 300 ^oC, collecting samples every 50^oC
[2] In, Ni and Fe K-edge under H₂/He atmosphere in from250^oC to 500 ^oC, collecting samples every 50^oC
[3] In, Ni and Fe K-edge under CO₂/He atmosphere in from250^oC to 500 ^oC, collecting samples every 50^oC

結果と考察 / Results and Discussion

The In K-edge EXAFS spectrum of In/NiO showed In-O bonds at 1.63 Å (Fig. 1b), confirming that In extracted lattice oxygen from the NiO surface during preparation, consistent with the XRD results（Fig.1a）. Notably, compared to standard In₂O₃, the In/NiO catalyst had shorter In-O bond length, and lacked characteristic In-O-In bonds in the 2-4 Å range, indicating the absence of long-range order of the surface In-O species. After thermal treatment, In/NiO-T exhibited both decreased In-O peak intensity and shortened In-O bond length. Furthermore, Ni K-edge EXAFS spectra showed that the In/NiO-T maintained a stable average Ni-O coordination number after calcination, indicating that metallic In primarily affected the NiO surface structure rather than its bulk properties (Fig. 1c).
In K-edge EXAFS spectra of In/NiO-T (Fig. 2a) showed rapidly disappearance of the In-O bond and emergence of a new peak at 2.2 Å, attributable to metallic In-Ni bonds based on XRD results. XANES spectra fitting, used to track the average valence state of Ni change over time, revealed distinct reduction patterns: In/NiO-T catalyst showed rapid initial NiO reduction that later slowed, while pristine NiO maintained a steady reduction rate (Fig. 2b, 2c). This disparity likely stemmed from the inductive effect of In species-In atoms extracted lattice oxygen from the NiO surface, accelerating initial reduction process. 

図・表・数式 / Figures, Tables and Equations

Fig. 1. (a) XRD patterns of 15% In/NiO and 15% In/NiO-T samples. -T indicated that the catalysts were calcined under Ar atmosphere at 350 ℃ for 2 h. (b) Fourier-transformed k³-weighted In K-edge and (c) Ni K-edge EXAFS spectra of In/NiO and In/NiO-T, respectively.

Fig.2. (a) In-situ In K-edge EXAFS spectra of In/NiO-T at 400 ^oC under CO₂/H₂ atmosphere. (b) Part of in-situ Ni K-edge XANES spectra over time at 400 ^oC under CO₂/H₂ atmosphere. The numbers of the color bar are white line intensity of XANES spectra. (c) The Ni valence change during the reaction determined by XANES linear combination fitting.

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

N．A．

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件