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

Abstract

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.

Recent advances in methodologies and applications of cataluminescence sensing

“…Generally speaking, CTL-based sensors since their inception have been established mainly for specific gas detection. CTL sensors based on the sensing elements of nanomaterials have broad application for monitoring various VOCs [50] including alcohols [29,[51][52][53][54] , aldehydes [55,56] , ketones [28,[57][58][59][60][61][62] , esters [63] , ethers [64][65][66] , acids [67] , hydrocarbon [47,68,69] , halohydrocarbon [70] , and inorganic small molecule gases [71] , including H 2 S [72][73][74][75][76][77] and CO [21,48,78] , all of which have contributed significantly to environmental monitoring. In addition, the selective detection of some analytes has also functioned to promote medical research and clinical diagnosis.…”

Novel Diethyl Ether Gas Sensor Based on Cataluminescence on Nano-Pd/ZnNi3Al2O7

“…CTL, a kind of chemiluminescence (CL) emitted from heterogeneous catalytic oxidation reactions on the gas–solid interface, has been considered as a promising energy transduction mechanism for fabricating gas sensors . In recent years, a series of CTL sensing applications have been attempted to develop for diethyl ether − and many other molecules − at different laboratories. However, a higher working temperature above 200 °C is not conducive to the stability of the sensor signal …”

Sensitive Carbon Monoxide Gas Sensor Based on Chemiluminescence on Nano-Au/Nd2O3–Ca3Nd2O6: Working Condition Optimization by Response Surface Methodology

“…It is a promising technology for making gas sensors . In recent years, a series of rapid analytical applications of CL on catalysts have been developed for CO − and many other molecules − at different laboratories. When using catalysts − to research and make a CO gas sensor, high working temperature becomes a main obstacle.…”

“…In recent years, a series of rapid analytical applications of CL on catalysts have been developed for CO − and many other molecules − at different laboratories. When using catalysts − to research and make a CO gas sensor, high working temperature becomes a main obstacle. Generally, sensors need to be as small or even miniaturized as possible in order to be portable, which implies that they must be a small heat capacity system.…”

“…Our previous work has proposed that the baseline instability will occur in a small heat capacity system when the working temperature exceeds 200 °C . In the past, the working temperature for CL on catalysts was usually more than 250 °C. − These sensitive materials they use have almost no CL activity below 200 °C, so they are not suitable for making CL gas sensors. Au-doped composites often exhibit catalytic oxidation activities at low temperature for CO − and many molecules. − In addition to Au, other noble metals, such as Pd, Pt, and Ag, show a similar performance.…”