Biomimetic Flower-Petal-Architected Zn-Based Nanocatalysts for Selective Oxidation of Glycerol to 1,3-Dihydroxyacetone

Catalytic activity is governed by surface phenomena, where tailored morphology and facet engineering synergistically regulate reaction pathways through electronic structure modulation and active site optimization. Inspired by the microstructural biomimetics of petal surfaces, this study synthesized three biomimetic ZnO nanocatalysts with distinct morphologies, specifically, flake flowers (FF), spherical flowers (SF), and rod flowers (RF), via a hydrothermal method. These architectures enabled the controlled exposure of three crystallographic facets (101), (100), and (110) on ZnO supports, creating unique electronic environments and surface oxygen vacancies at the Au–ZnO interfaces. Notably, the ZnO (110) facet in the Au/ZnO-RF nanocatalyst facilitates enhanced electron storage from Au nanoparticles (Au NPs), synergizing with oxygen vacancies to strengthen O2 and glycerol adsorption. Concurrently, the activated O2 species efficiently extracted hydrogen from key intermediates on the ZnO (110) crystal facets. As a result, the Au/ZnO-RF nanocatalyst achieves exceptional catalytic performance in glycerol oxidation, with a 91.1% glycerol conversion rate and 76.2% selectivity toward 1,3-dihydroxyacetone (DHA), which is the best Au/ZnO nanocatalyst at present. Comprehensive characterization and experimental analyses confirm that RF ZnO with high crystallinity and enriched adsorbed oxygen species plays a pivotal role in facilitating efficient electron–hole transport, lowering reduction temperatures, and suppressing Au NPs aggregation.

https://pubs.acs.org/doi/abs/10.1021/acsanm.5c01734