Subject Number : S-16-NM-0004
Support Type : 機器利用
Proposal Title (English) : Novel catalyst for CO2 reduction
Username (English) : Zhongli Wang
Affiliation (English) : JSPS

1. Summary
The purpose of this research is to synthesize novel catalysts for CO2 reduction. Electrochemical reduction of carbon dioxide powered by renewable electricity represents a promising solution for energy and environmental sustainability. To enable this technology, active and selective catalysts must be developed. Noble metals exhibit excellent activity but are hampered by their low abundance and high cost. Thus, searching for efficient nonprecious metal catalysts is vital for practical applications. In this project, the SnO2/C composite materials are synthesized for CO2 reduction.

2. Experimental
The used equipments are NMR and Freeze dryer.
Metal nanoparticles were synthesized by a modification of a facile hydrothermal method.
The appropriate amount of Tin(II) chloride (SnCl2) precursor was dissolved in ethylene glycol with trace amount of water, mixed with appropriate amount of carbon nanofibers prepared by electrochemical polymerization and carbonization of PPY; or graphene prepared by a thermal expansion method reported in the literature, and then ultrasonicated for ~30 min. The resulting mixture was heated up to 190 oC and then refluxed with vigorous stirring. The product was collected by ultrafiltration and washed with deionized water.
The freeze dryer was used to dry samples and the NMR was used measure the reduction products of CH3COOH, CH3OH, CH3CH2OH, and so on.

3. Results and Discussion
TEM images show the synthesized SnO2 NPs are ∼10 nm average diameter, uniformly deposited on the surface of the carbon support. The high-resolution Sn3d XPS spectrum exhibits binding energies at 496.5 and 488.0 eV that can be assigned to Sn3d3/2 andSn3d5/2 ionizations, respectively. The three intense diffraction peaks in the XRD pattern shown at 26.2°, 33.7°, and 51.2° can be indexed as the (110), (101), and (211) planes of the polycrystalline rutile SnO2 structure, respectively. Electrocatalytic CO2 reduction by SnO2/C composite catalyst was evaluated in 0.1 M KHCO3 aqueous solutions. In aqueous NaHCO3 solutions, maximum Faradaic efficiencies for formate production of 60% have been reached with current densities of 6 mA/cm2.

4. Others
Platform staffs kindly provided instructions how to use equipment.

5. Publication/Presentation
(1) Z. L. Wang, C. Li, Y. Yamauchi,
Nanostructured nonprecious metal catalysts for electrochemical reduction of carbon dioxide, Nano today, 11, 3(2016), 373–391.

6. Patent
N/A