【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

24HK0068

利用課題名 / Title

Development of heterogeneous catalysts for conversion of CO₂ and biomass 

利用した実施機関 / Support Institute

北海道大学 / Hokkaido Univ.

機関外・機関内の利用 / External or Internal Use

内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)

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）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）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

キーワード / Keywords

触媒科学/Catalysis,表面・界面・粒界制御/ Surface/interface/grain boundary control,電子顕微鏡/ Electronic microscope

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)

Shrotri Abhijit

所属名 / Affiliation

北海道大学　触媒科学研究所

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

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

大多 亮,谷岡 隆志

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）-

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

HK-101：ダブル球面収差補正走査透過型電子顕微鏡
HK-107：量子・電子制御ナノマテリアル顕微物性測定装置

報告書データ / Report

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

High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy (HAADF-STEM) is an important tool for studying the structure catalysts and nanomaterials at the atomic scale. In this study, we used HAADF-STEM to analyze a dual-atom catalyst, Co-Zn-ZrO₂, for CO₂ hydrogenation to methanol. The aim of the study was to assess the dispersion, composition, and dispersion of Co and Zn atoms within the ZrO₂ matrix. The absence of nanoparticles of oxide phases is important for high catalytic activity. (HAADF-STEM imaging, coupled with elemental mapping, was used to confirm the incorporation of Co²⁺ and Zn²⁺ into the ZrO₂ lattice.

実験 / Experimental

The Co-Zn-ZrO₂ catalyst was synthesized through a co-precipitation method, followed by drying, calcination, and subsequent structural characterization. HAADF-STEM analysis was performed by using high resolution Cu grid to disperse the sample using ethanol. Elemental mapping was used to determine the dispersion and loading of corresponding elements. 

結果と考察 / Results and Discussion

The HAADF-STEM image of the Co-Zn-ZrO₂ catalyst showed only the tetragonal ZrO₂ (t-ZrO₂) phase, and the absence of separate ZnO, CoO, and Co₃O₄ phases confirmed the incorporation of Co and Zn into the ZrO₂ lattice. Elemental mapping further confirmed the homogeneous distribution of Co and Zn atoms within the ZrO₂ matrix. Homogeneous distribution of dopants is crucial to create uniform active sites necessary to prevent byproduct formation.  Co incorporation creates active sites that regulate CO₂ adsorption and formate stabilization, while Zn, free from poisoning, efficiently dissociates H₂ to hydrogenate formate into methanol. The catalyst exhibited excellent stability during a 100-hour catalytic test under varying reaction conditions. HAADF-STEM image and elemental mapping of used catalyst further confirmed that there was no agglomeration of Co or Zn species after then reaction.Under optimized conditions (320 °C, 5 MPa, and 120,000 mL h⁻¹ gcat⁻¹), Co-Zn-ZrO₂ catalyst achieved a methanol space-time yield (STY) of 1.5 gMeOH h⁻¹ gcat⁻¹, which is among the highest STYMeOH reported for oxide catalysts. The presence of single Co atoms, as confirmed by HAADF-STEM, regulates CO₂ adsorption and formate stabilization, preventing Zn from poisoning by intermediate adsorption and enabling efficient H₂ dissociation and formate hydrogenation to methanol. 

図・表・数式 / Figures, Tables and Equations

Figure 1. (a) XRD of all dual-atom doped oxides and Zn-ZrO₂. (b) Shifting of the (101) reflection of t-ZrO₂ in XRD due to doping. (c) HAADF-STEM image of Co-Zn-ZrO₂ showing the (110) plane of t-ZrO₂ and the corresponding d spacing. (d) HAADF-STEM image of Co-Zn-ZrO₂ with elemental mapping of (e) Co, (f) Zn and (g) Zr.

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

This work was supported by JSPS Grant-in-Aid for Scientific Research (C) KAKENHI JP22K04821 and research funding from The Japan Petroleum Institute. This work was also supported by the Iketani Science and Technology Foundation. A part of this work was supported by “Advanced Research Infrastructure for Materials and Nanotechnology in Japan (ARIM)” of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Grant Number JPMXP122HK0089, JPMXP124HK0068 (Hokkaido University). The authors extend their gratitude to the technical staff at the STEM facility for their assistance with microscopy analysis.

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)

1. Nazmul Hasan MD Dostagir, Enhanced methanol production via selective hydrogen utilization during CO2 hydrogenation over Co containing dual-atom doped oxide catalyst, , , (2024).
   DOI: 10.26434/chemrxiv-2024-3c388
   
2. Yayati Naresh Palai, Strong metal support interaction in Ru/V2O3 catalyst reduces reactant induced poisoning during succinic acid hydrogenation, , , (2024).
   DOI: 10.26434/chemrxiv-2024-r2tc4-v2
   

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

1. 1. Abhijit Shrotri Mitigating the poisoning effect of formate during CO2 hydrogenation using cobalt containing dual atom oxide catalysts Conference on Advances in Chemistry for Energy and Environment (CACEE -2024), Mumbai, India 2024年12月17日
2. 2. Abhijit Shrotri Doped Oxide Catalysts for hydrogenation of CO2 International Conference on Carbon Capture and Utilization (ICCCU24), Bangalore, India, 2024年12月12日

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