Entropy-stabilized single-atom Pd catalysts via high-entropy fluorite oxide supports.

Xu, Haidi; Zhang, Zihao; Liu, Jixing; Do-Thanh, Chi-Linh; Chen, Hao; Xu, Shuhao; Lin, Qinjing; Jiao, Yi et al. · Nat Commun · 2020

basic_science · Level V

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Abstract

Single-atom catalysts (SACs) have attracted considerable attention in the catalysis community. However, fabricating intrinsically stable SACs on traditional supports (N-doped carbon, metal oxides, etc.) remains a formidable challenge, especially under high-temperature conditions. Here, we report a novel entropy-driven strategy to stabilize Pd single-atom on the high-entropy fluorite oxides (CeZrHfTiLa)O<sub>x</sub> (HEFO) as the support by a combination of mechanical milling with calcination at 900 °C. Characterization results reveal that single Pd atoms are incorporated into HEFO (Pd<sub>1</sub>@HEFO) sublattice by forming stable Pd-O-M bonds (M = Ce/Zr/La). Compared to the traditional support stabilized catalysts such as Pd@CeO<sub>2</sub>, Pd<sub>1</sub>@HEFO affords the improved reducibility of lattice oxygen and the existence of stable Pd-O-M species, thus exhibiting not only higher low-temperature CO oxidation activity but also outstanding resistance to thermal and hydrothermal degradation. This work therefore exemplifies the superiority of high-entropy materials for the preparation of SACs.