Facile Synthesis of Microporous Carbons from Biomass Waste as High Performance Supports for Dehydrogenation of Formic Acid

Carbon-coated silica supported palladium for hydrogen production from formic acid - Exploring the influence of strong metal support interaction

Hydrogen energy is one of the most promising energy carriers to solve the increasingly severe energy crisis. Formic acid decomposition (FAD) solves the storage and transportation problems of hydrogen gas since hydrogen can be produced from aqueous formic acid under mild conditions. To efficiently convert formic acid to hydrogen gas, chemical and structural modification of Pd nanoparticles or supports have been carried out, especially introducing the strong metal support interaction (SMSI). Herein, we synthesized core-shell structured SiO2@SC compounds as the supports to introduce SMIS to Pd/PdO nanoparticles. The relationship between FAD activity and SMSI is investigated. The SMSI between Pd/PdO nanoparticles and SiO2/SC is adjusted by altering the thickness of the carbon layer. The X-ray photoelectron spectroscopy shows that owing to the strong electron-attracting ability SiO2 core contributes to leading the Pd0 active site in an electron-deficient state. The thickness of the carbon layer controls the ratio of Pd0/PdO, which enhances the anti-poisoning ability of the catalyst. Owing to the electron-deficient state of Pd0 and optimal ratio of Pd0/PdO, the hydrogen desorption rate of FAD on Pd is enhanced, and the turn over frequency of Pd/SiO2@SC-1:3 catalyst reaches 1138 h-1, which is ten times higher than that of the pristine Pd/SC catalyst. These results are believed to guide the design and development of highly active Pd-based catalysts for hydrogen generation via FAD.

Sawdust-Derived Activated Carbon with Hierarchical Pores for High-Performance Symmetric Supercapacitors

The recyclable utilization of waste biomass is increasingly important for the development of a sustainable society. Here, the sawdust-derived activated carbon (SD-AC) has been prepared via a convenient H₃PO₄-based activation method and further trialed as an electrode for use as a high-performance symmetric supercapacitor. The as-prepared SD-AC possesses a hierarchically porous structure with micropores (0.55 nm) and mesopores (2.58 nm), accounting for its high specific surface area of 621 m² g⁻¹, with a pore volume of 0.35 cm³ g⁻¹. Such a hierarchically porous structure can offer a favorable pathway for fast ion penetration and transportation, enhancing its electrochemical performance. As a result, the SD-AC electrode exhibits a maximum specific capacitance of up to 244.1 F g⁻¹ at 1.0 A g⁻¹, a high rate capability (129.06 F g⁻¹ at 20 A g⁻¹), and an excellent cycling performance, with 87% retention over 10,000 cycles at 10 A g⁻¹. Of particular note is that the SD-AC-based symmetric supercapacitor achieves a maximum energy density of 19.9 Wh kg⁻¹ at the power density of 650 W kg⁻¹, with a long-term cycle lifespan. This work showcases the recyclable utilization of waste biomass for the preparation of high-value activated carbon for efficient energy storage.