Demonstrating the Potential of Chemiluminescence as a Tool to Characterize Heterogeneous Catalysis Using CO Oxidation on Copper‐Based Catalysts as an Example

• Published in: ChemCatChem 2019-05, Vol.11 (10), p.2423-2426
• Main Authors: Kato, Satoru, Ito, Yoshihiko, Ikuta, Yasuhiro, Morikawa, Akira, Suda, Akihiko, Tanabe, Toshitaka
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Catalysis; Catalysts; Chemical reactions; Chemiluminescence; CO oxidation; Copper; Copper oxides; Heterogeneous catalysis; Luminescence; Organic chemistry; Oxidation; Reaction mechanisms; Silicon dioxide; Titanium dioxide
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201900264

In this paper, the potential of chemiluminescence (CL) as a tool to determine reaction mechanisms of heterogeneous catalyst is demonstrated. Since CL is emitted from excited species produced in chemical reactions, the analysis of CL is expected to be informative for investigating reaction mechanisms. As a representative example, CL under CO oxidation over copper‐based catalysts was measured. The reaction mechanism of copper‐based catalysts reportedly depends on the support material. CL was observed with CuO/Al2O3 and CuO/SiO2−Al2O3 but was not detected with CuO, CuO/TiO2 and CuO/SiO2. Transient CL emitting analysis for CuO/Al2O3 revealed that CL was emitted via an Eley‐Rideal (ER) mechanism. Although the CO oxidation mechanism over CuO/SiO2−Al2O3 has not been reported, CO oxidation via an ER mechanism was suggested based on the similarities of the CL spectra of CuO/SiO2−Al2O3 and CuO/Al2O3. This suggests the potential of CL as a tool to investigate reaction mechanisms of heterogeneous catalysts. Shedding a light: When a CuO nanoparticle oxidizes CO via the Eley‐Rideal mechanism, chemiluminescence in the range of 500 nm–700 nm is observed. This means potential of chemiluminescence for an indicator to detect the reaction mechanism.