Non-noble metal clusters supported on titanium phthalocyanines for ammonia decomposition: A first-principles study

Abstract

This study examined NH3 decomposition over the metal clusters on titanium phthalocyanines (M6@TiPc; M6 = Fe6, Co6, Ni6, Co5Ni, and Ni5Co). The M6 metal clusters could stably adsorb on TiPc. The Brønsted–Evans–Polanyi relations were found in the dehydrogenation step and the step for associative desorption of nitrogen. The latter was the rate-determining step for decomposing NH3. Moreover, the positive electric field promoted the dehydrogenation step by weakening the adsorption strength of NH3. In contrast, the negative electric field improved the step for associative desorption of nitrogen by reducing the adsorption strength of nitrogen. Overall, this study offers insight into the design of the high-performance M6@TiPc-based catalyst for decomposing NH3.