PtPd Atomic Layer Shelled PdCu Hollow Nanoparticles on Partially Unzipped Carbon Nanotubes for Breaking the Activity-Stability Trade-Off toward the Hydrogen Oxidation Reaction in Alkaline Media.

Developing highly active yet stable catalysts for the hydrogen oxidation reaction (HOR) in alkaline media remains a significant challenge. Herein, we designed a novel catalyst of atomic PtPd-layer shelled ultrasmall PdCu hollow nanoparticles (HPdCu NPs) on partially unzipped carbon nanotubes (PtPd@HPdCu/W-CNTs), which can achieve a high mass activity, 5 times that of the benchmark Pt/C, and show exceptional stability with negligible decay after 20,000 cycles of accelerated degradation test. The atomically thin PtPd shell serves as the primary active site for the HOR and a protective layer that prevents Cu leaching. Additionally, the HPdCu substrate not only tunes the adsorption properties of the PtPd layer but also prevents corrosive Pt from reaching the interface between NPs and the carbon support, thereby mitigating carbon corrosion. This work introduces a new strategy that leverages the distinct advantages of multiple components to address the challenges associated with slow kinetics and poor durability toward the HOR.

Advanced Nanocarbons Toward two-Electron Oxygen Electrode Reactions for H2O2 Production and Integrated Energy Conversion.

Hydrogen peroxide (H2O2) plays a pivotal role in advancing sustainable technologies due to its eco-friendly oxidizing capability. The electrochemical two-electron (2e-) oxygen reduction reaction and water oxidation reaction present an environmentally green method for H2O2 production. Over the past three years, significant progress is made in the field of carbon-based metal-free electrochemical catalysts (C-MFECs) for low-cost and efficient production of H2O2 (H2O2EP). This article offers a focused and comprehensive review of designing C-MFECs for H2O2EP, exploring the construction of dual-doping configurations, heteroatom-defect coupling sites, and strategic dopant positioning to enhance H2O2EP efficiency; innovative structural tuning that improves interfacial reactant concentration and promote the timely release of H2O2; modulation of electrolyte and electrode interfaces to support the 2e- pathways; and the application of C-MFECs in reactors and integrated energy systems. Finally, the current challenges and future directions in this burgeoning field are discussed.

Sulfur-bridge ligands altering the microenvironment of single-atom CoN3S sites to boost the oxygen reduction reaction.

We report here an asymmetric N,S-coordinated cobalt-based single-atom catalyst with sulfur (S)-bridge ligands (Co-N/S-C) for the oxygen reduction reaction (ORR). The Co-N/S-C exhibits a half-wave potential (E1/2) of 0.908 V versus RHE, outperforming most state-of-the-art ORR catalysts. Theoretical calculations indicate that the CoN3SC10-S moiety facilitates the ORR kinetics by optimizing the adsorption of intermediates. This work provides new insights into the design of single-atom catalysts for electrocatalysis through heteroatom-bridge ligand engineering.

Stable and High-performance Flow H2-O2 Fuel Cells with Coupled Acidic Oxygen Reduction and Alkaline Hydrogen Oxidation Reactions.

Conventional H2-O2 fuel cells suffer from the low output voltage, insufficient durability, and high-cost catalysts (e.g., noble metals). Herein, this work reports a conceptually new coupled flow fuel cell (CF-FC) by coupling asymmetric electrolytes for acidic oxygen reduction reaction and alkaline hydrogen oxidation reaction. By introducing an electrochemical neutralization energy, the newly-developed CF-FCs possess a significantly increased theoretical open-circuit voltage. Specifically, a CF-FC based on a typical transition metal single-atom Fe-N-C cathode catalyst demonstrates a high electricity output up to 1.81 V and durability with an ultrahigh retention of 91% over 110 h, far superior to the conventional fuel cells (usually, < 1.0 V, < 50% retention over 20 h). The output performance can even be significantly enhanced easily by connecting multiple CF-FCs into the parallel, series, or combined parallel-series connections at a fractional cost of that for the conventional H2-O2 fuel cells, showing great potential for large-scale practical applications. Thus, this study provides a platform to transform conventional fuel cell technology through the rational design and development of advanced energy conversion and storage devices by coupling different electrocatalytic reactions.

Ligand-engineering Cu-based catalysts to accelerate the electrochemical reduction of CO2.

Two typical Cu-based complex catalysts with piperazine (PR) and p-phenylenediamine (pPDA) ligands were designed to elucidate whether the ligands can tailor the reduction behavior of the Cu species and thus modulate their electrochemical CO2 reduction reaction (eCO2RR) activity. Specifically, Cu-PR underwent a significant in situ transformation into Cu nanoparticles enriched with a Cuδ+/Cu0 interface for high eCO2RR activity, compared to Cu-pPDA. This finding reveals the importance of ligand engineering in modulating the eCO2RR performance of Cu-based complexes.

Unveiling the Role of Cationic Pyridine Sites in Covalent Triazine Framework for Boosting Zinc-Iodine Batteries Performance.

Rechargeable Zinc-iodine batteries (ZIBs) are gaining attention as energy storage devices due to their high energy density, low-cost, and inherent safety. However, the poor cycling performance of these batteries always arises from the severe leakage and shuttle effect of polyiodides (I3 - and I5 -). Herein, a novel cationic pyridine-rich covalent triazine framework (CCTF-TPMB) is developed to capture and confine iodine (I2) species via strong electrostatic interaction, making it an attractive host for I2 in ZIBs. The as-fabricated ZIBs with I2 loaded CCTF-TPMB (I2@CCTF-TPMB) cathode achieve a large specific capacity of 243 mAh g-1 at 0.2 A g-1 and an exceptionally stable cyclic performance, retaining 93.9% of its capacity over 30 000 cycles at 5 A g-1. The excellent electrochemical performance of the ZIBs can be attributed to the pyridine-rich cationic sites of CCTF-TPMB, which effectively suppress the leakage and shuttle of polyiodides, while also accelerating the conversion reaction of I2 species. Combined in situ Raman and UV-vis analysis, along with theoretical calculations, clearly reveal the critical role played by pyridine-rich cationic sites in boosting the ZIBs performances. This work opens up a promising pathway for designing advanced I2 cathode materials toward next-generation ZIBs and beyond.

An Outlook on Platinum-Based Active Ingredients for Dermatologic and Skincare Applications.

Platinum-based materials exhibit a broad spectrum of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and pro-collagen synthesis properties, making them particularly useful for various biomedical applications. This review summarizes the biological effects and therapeutic potential of platinum-based active ingredients in dermatological and skincare applications. We discuss their synthesis methods and their antioxidant, anti-inflammatory, antimicrobial, and collagen synthesis properties, which play essential roles in treating skin conditions including psoriasis and acne, as well as enhancing skin aesthetics in anti-aging products. Safety and sustainability concerns, including the need for green synthesis and comprehensive toxicological assessments to ensure safe topical applications, are also discussed. By providing an up-to-date overview of current research, we aim to highlight both the potential and the current challenges of platinum-based active ingredients in advancing dermatology and skincare solutions.