Multivariate analysis on the structure-activity parameters for nano CuO_x-catalyzed reduction reactions

Understanding the origin of enhanced catalytic activity is critical to heterogeneous catalyst design. This is especially important for non-noble metal-based catalysts, notably metal oxides, which have recently emerged as viable alternatives for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to increased surface area and oxygen vacancies. Concomitantly, the treatments that induce oxygen vacancies also impact other material parameters such as microstrain, crystallinity, oxidation state, and particle shape. Herein, multivariate statistical analysis is used to disentangle the impact of material properties of CuO nanoparticles on catalytic rates for nitroaromatic reduction and methylene blue reduction. The impact of microstrain, shape, and Cu(0) atomic percent are demonstrated for these reduction reactions; furthermore, a protocol for correlating material parameters to catalytic efficiency is presented and the importance of catalyst design for these broadly utilized probe reactions is highlighted.