Critical downstream catalytic processes for an NH3 economy

Abstract

Ammonia (NH₃) is among the most promising green energy carriers, due to its high energy density, ease of liquification, and existing know-hows for its large-scale synthesis, transportation, and storage. However, to effectively harness NH₃ as an energy source, many downstream processes still need further development. This review highlights the barriers and challenges in two of the critical catalytic processes, namely ammonia decomposition and catalytic ammonia combustion. In the first part, we discuss the challenges of obtaining high purity and high-pressure hydrogen via ammonia decomposition in various application scenarios. Then, we discuss the potential roles of ammonia decomposition and catalytic ammonia combustion in the processes where NH₃ is directly used as a combustion fuel. Understanding and further optimizing these catalytic processes are crucial to facilitate an NH₃ economy, thereby fostering a more environmentally conscious energy landscape.