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 candidates for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to an increased surface area and the presence of oxygen vacancies. Concomitantly, the treatments that induce oxygen vacancies also impact other material properties, such as the 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 and methylene blue reduction. The impact of the microstrain, shape, and Cu(0) atomic percent is demonstrated for these reactions; furthermore, a protocol for correlating material property parameters to catalytic efficiency is presented, and the importance of catalyst design for these broadly utilized probe reactions is highlighted.