TEMPO‐Oxidized Cellulose Nanofibers as Pseudocatalysts for in Situ and on‐Demand Hydrogen Generation via Aluminum Powder/Pure Water Reactions at a Temperature below 50 °C

Cellulose nanofibers (CNFs) prepared via 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation of the C6 primary hydroxyls native cellulose to carboxylates are used as pseudocatalysts for enhancing aluminum powder/pure water reactions. The Al reaction is a stepwise reaction. It starts from hydration outmost Al2O3 thin layer and then inner metallic with water. At lower temperatures (<50 °C), OH− Al3+ ions preliminary products hydration. Once powders mixed pure containing 0.1–0.5 wt% TEMPO-CNFs, condensed networks consisting TEMPO-CNFs self-establish over layer. captured by formation insoluble Al3+/TEMPO-CNFs complexing nanostructures conjugated being restricted nearby Al2O3-based electrostatic repulsion. A highly alkaline condition (pH > 11) dynamically generated, result, dissolves rapidly ions. function also catalysts, accelerating (2–200 μm) react promptly nearly 100% Al/H2 conversion obtained at temperature below 50 °C.