Support-controlled microwave energy localization enables efficient and responsive ammonia cracking

作者：S Kuramoto, Ryo Ishibashi, H Tamiya, Seunghwan Jung, Yasuhiro Sakamoto, Hiroki Yamada, Tatsuya Shinagawa, Masayuki Kawagoe, Hirokazu Matsuda, Chihiro Hiraiwa, Fuminao Kishimoto, Kazuhiro Takanabe · 发表于：ChemRxiv · 年份：2026 · DOI：10.26434/chemrxiv.15006589/v1 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Catalysts for Methane Reforming、Catalysis for Biomass Conversion

Renewable-electricity-powered hydrogen supply chains require compact, efficient, and demand-responsive NH3 crackers. Here we develop a microwave-driven ammonia decomposition system based on an LTA-type zeolite catalyst loaded with 10 wt% Ru nanoparticles that directly converts electrical energy into chemical energy through localized catalyst heating. The system achieves an external energy conversion efficiency of 48%, based on the net microwave input power after subtracting the reflected power. Thermal simulations further reveal an internal energy conversion efficiency of 60%, based on the microwave energy absorbed by the catalyst, independent of microwave frequency, corresponding to a hydrogen production efficiency of 92% on a lower heating value (LHV) basis. The reactor maintains high reaction rates while keeping the reactor wall at only 450 °C, enabling the use of conventional stainless steels. Multiphysics simulations combined with in situ synchrotron total scattering reveal that the dielectric properties of the zeolite support promote efficient power-to-chemical energy conversion by localizing electromagnetic energy within the catalyst. Fast start-up, rapid shutdown, and stable operation under fluctuating power demonstrate a compact and demand-responsive platform for decentralized hydrogen production compatible with renewable electricity.