Recent Trends and Perspectives in Palladium Nanocatalysis: From Nanoparticles to Frameworks, Atomically Precise Nanoclusters and Single-Atom Catalysts

Palladium is one of the most utilized metals in catalysis, particularly for hydrogenation and oxidation, cross C–C coupling, hydrogen formation, photocatalytic and electrocatalytic energy conversion reactions. Heterogeneous catalysis is undergoing a considerable move involving molecular aspects, which allows a better control and understanding of the structure–reactivity relationship toward optimization of the catalyst performances and selectivities. Inspired by organometallic catalysis, nanocatalytic materials that provide heterogeneization, nanocatalyst stabilization and optimized synergies include iron oxides, polymers, dendrimers, magnetic iron oxides, metal–organic and covalent-organic frameworks, carbons, atomically precise nanoclusters and other subnanoclusters such as single atoms, dual atoms and their combination and synergies with nanoparticles. In these nanocomposites, the number of catalytically utilized expansive Pd atoms is minimized. This mini-review addresses new trends of Pd nanocatalysis including these aspects with selected examples and examines perspectives.

Progress of Pd nanocatalysis are reviewed including dramatic recent decrease of Pd sub-nanoparticle size utilizing modern organic or inorganic framework matrices.