Cataluminescence-Based Array Imaging for High-Throughput Screening of Heterogeneous Catalysts

High-throughput screening of catalysts could dramatically improve performance and reduce costs in the discovery and study of various catalysts. Here we report a cataluminescence-based array imaging as a high-throughput screening technique in the combinatorial discovery of active catalysts for CO oxidation. This strategy is based on the fact that the CO oxidation generates cataluminescence emission on the surface of nanomaterials, whose intensity is correlated to the activity of the catalyst. To demonstrate the feasibility of the cataluminescence-based array imaging for high-throughput screening of catalysts, different nanosized metal catalysts supported on TiO2 nanoparticles were prepared. These catalysts include monometallic Au, Pt, and the bimetallic Au-Pt heteroaggregate catalysts, at total metal loadings of 0.5%, 1.0%, and 2.5%, and with atomic ratios of 1:1, 1:2, and 2:1 (Au/Pt). A 4 x 4 array was integrated by depositing these nanosized catalysts onto the ceramic chip, and the brightness of each spot in the image was recorded. The catalytic activities of those catalysts for the CO oxidation were evaluated parallelly by both the cataluminescence imaging and the gas chromatography method. The correlation coefficient is 0.914 for the two techniques, indicating that the cataluminescence imaging technique can be applied for the evaluation of the catalytic activities. Moreover, fast evaluation of multiple catalysts at a series of working temperature can be achieved by this cataluminescene-based array imaging. With the development of nanotechnology as well as the catalyst industry, the cataluminescence-based array imaging will address its importance in the high-throughput screening of catalysts.