One-Pot Synthesis of Hexamethylenetetramine Coupled with H2Evolution from Methanol and Ammonia by a Pt/TiO2Nanophotocatalyst

Abstract

Utilization of solar energy for photocatalytic H2evolution coupled with value-added chemical synthesis is a promising avenue to address energy and environmental crises. Here, we report the hexamethylenetetramine (HMT) synthesis and H2evolution from methanol and ammonia in one pot using a nanophotocatalyst of the conventional semiconductor TiO2(P25) loaded with Pt (Pt/P25). The addition of ammonia inhibits byproduct ethylene glycol formation, promotes H2evolution, and obtains HMT with high selectivity (>99.0%). The Pt valence state is regulated by calcination and reduction treatment, indicating that Pt/P25 is a stable catalyst for the photocatalytic synthesis of HMT from methanol and ammonia. The optimized formation rates of H2and HMT are 71.53 and 11.39 mmol gcat-1h-1, respectively. This work provides a green and sustainable pathway for the photocatalytic HMT synthesis coupled with H2evolution under mild conditions.