Pt‐Like Oxygen Reduction Activity Induced by Cost‐Effective MnFeO 2 /N‐Carbon

Agar-induced hollow porous carbon nanospheres anchored platinum for high-performance hydrogenation

Hollow porous carbon has attracted a great deal of interest as catalyst-support because of its high surface area, low density and large pore volume. Herein, we develop a layer-by-layer assembly method to effectively load Pt nanoparticles on hollow porous carbon nanospheres (Pt/HPC) through using modified-SiO₂ nanospheres as the template and agar as the carbon resource. The gel properties of agar (e.g., sensitivity to temperature and high mechanical strength) makes the Pt nanoparticles well crosslink with carbon, as well as endows the carbon nanospheres with robust stability. The synthesized Pt/HPC was employed as a catalyst in the hydrogenation reduction of rhodamine B (RhB). The catalytic results demonstrate that Pt/HPC is very promising for RhB hydrogenation as compared to commercial Pt/C catalyst. It is proven that such excellent activity of Pt/HPC can be attributed to the combined merits of hollow porous architecture and well combination between HPC and Pt nanoparticles.

Concave PtCo nanooctahedra with high-energy {110} facets for the oxygen reduction reaction

For the first time, iminodiacetic acid serves as a morphology control agent for the synthesis of concave PtCo nanooctahedra.

Catalytically Active Carbon From Cattail Fibers for Electrochemical Reduction Reaction

Catalytically active carbons derived from plant biomass are conducive to the construction of renewable energy source system and utilization of sustainable resources. In this article, natural cattail fibers are used to fabricate porous nitrogen-doped carbon via direct chemical activation and heteroatom modification treatments. The graphene-like sheets from biomass pyrolysis are assembled into three-dimensional carbon frameworks. The chemical activation of KHCO₃ generated unique porous structure and N-containing molecules pyrolysis modification provided nitrogen doping atoms. High surface area up to 2,345 m²·g⁻¹ with simultaneous hierarchical pores (from micro to meso and macro) with abundant edge defects are achieved for these carbon materials. These materials have a very large external surface area up to 1,773 m²·g⁻¹. The above strategy exhibits a significant synergistic effect on the improvement of catalytic properties toward hydrogen evolution reaction and oxygen reduction reaction. The small over potentials and Tafel slopes of these catalytically active carbons demonstrate excellent potential applications in renewable energy conversion and storage systems. This research established a new link among environmental improvement, biomass conversion and renewable energy utilization.

Immobilization of Fe-Doped Ni2P Particles Within Biomass Agarose-Derived Porous N,P-Carbon Nanosheets for Efficient Bifunctional Oxygen Electrocatalysis

A feasible and green sol-gel method is proposed to fabricate well-distributed nano-particulate Fe-Ni₂P incorporated in N, P-codoped porous carbon nanosheets (Fe-Ni₂P@N,P-CNSs) using biomass agarose as a carbon source, and ethylenediamine tetra (methylenephosphonic acid) (EDTMPA) as both the N and P source. The doped Fe in Ni₂P is essential for a substantial increase in intrinsic catalytic activity, while the combined N,P-containing porous carbon matrix with a better degree of graphitization endows the prepared Fe-Ni₂P@N,P-CNSs catalyst with a high specific surface area and improved electrical conductivity. Benefiting from the specific chemical composition and designed active site structure, the as-synthesized Fe-Ni₂P@N,P-CNSs manifests a satisfying catalytic performance toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in an alkaline solution, with low overpotential, small Tafel slope and long-term durability, relative to the counterparts (Fe-free Ni₁₂P₅/Ni₂P₂O₇@N,P-CNSs and CNSs) with single components and even comparable to Pt/C and RuO₂ catalysts. The present work broadens the exploration of efficient bifunctional oxygen electrocatalysts using earth abundant biomass as carbon sources based on non-noble metals for low cost renewable energy conversion/storage.