Perforated Pd Nanosheets with Crystalline/Amorphous Heterostructures as a Highly Active Robust Catalyst toward Formic Acid Oxidation.

Perforated ultrathin Pd nanosheets with crystalline/amorphous heterostructures are rationally synthesized to offer a large electrochemically active surface area of 172.6 m2 g-1 and deliver a 5.6 times higher apparent reaction rate in comparison to commercial Pd/C, thus offering a facile confined growth method to generate superior catalysts.

γ-Fe2O3 nanoparticles stabilized by holey reduced graphene oxide as a composite anode for lithium-ion batteries.

Integrating nanoscale active materials on conductive holey reduced graphene oxide (RGO) framework is an effective strategy to synthesize composite electrode materials for advanced lithium-ion batteries. Herein, a composite of γ-Fe2O3 nanoparticles stabilized by the engineered holes on RGO was successfully synthesized by using a facile in-situ etching route, which exhibited high lithium storage performance. The fundamental insight of its enhancement mechanism was discussed. This work offers a newly route to synthesize the composite of holey RGO confined metal oxide nanoparticles for the applications in lithium ion batteries and beyond.

Twisted palladium-copper nanochains toward efficient electrocatalytic oxidation of formic acid.

Twisted PdCu nanochains are synthesized successfully via a staged thermal treatment route, offering rich twin boundaries as catalytic "active sites" and modified electronic effects. Toward formic acid oxidation, the twisted PdCu nanochains hold the highest catalytic peak current density (1108.2 mA mg-1Pd) over previous reported PdCu alloy catalysts, and also much higher catalytic activity and durability comparing with Pd nanochains and commercial Pd/C. The catalytic enhancement mechanism to PdCu nanochains is proposed and discussed. Additionally, we found that the formation of PdCu nanochains follows a typical anisotropic growth approach, and the multiple steps of staged thermal treatment route displays a vital role in fabricating the unique PdCu nanochains while the introduced Cu precursors might affect the reduction rate of Pd species and act as deposition or nucleation sites for twisted structure in terms of rich twin boundaries. This work describes an efficient, low-Pd loading catalyst for electrooxidation of formic acid, and also demonstrates a universal method to fabricate other defect-rich catalysts for broad applications in energy conversion and storage systems and sensing devices.

Synthesis of defect-rich palladium-tin alloy nanochain networks for formic acid oxidation.

Unique and novel Pd4Sn nanochain networks were successfully synthesized with an average diameter of 5 nm, rendering a modified Pd electronic structure with rich defects such as atomic corners, steps or ledges as catalytic active sites for great enhancement of charge transfer and electrode kinetics. The prepared Pd4Sn nanochain networks held an electrochemically active surface area as high as 119.40 m2 g-1, and exhibited higher catalytic activity and stability toward formic acid oxidation compared with Pd3Sn nanochain networks, Pd5Sn nanochain networks, Pd4Sn dendrites and Pd/C. The fundamental insight of the enhancement mechanism is discussed, and this work offers a novel, less expensive but highly active catalyst for direct formic acid fuel cells.