Unraveling synergy between hierarchical pores and acidity in Beta zeolites for boosting urea‐to‐melamine conversion

Abstract Conventional solid catalysts for melamine synthesis from urea suffer from low activity and rapid deactivation. Herein, we developed a series of hierarchical Beta zeolites with tunable architectures (hollow and non‐hollow) and abundant acid sites via a facile hydrothermal strategy. The optimized hollow Ho‐B30 catalyst achieved a remarkable 92.3% melamine yield under mild conditions (400°C, 0.4 MPa), outperforming conventional microporous zeolite and industrial catalyst by 112.7% and 47.0%, respectively. Systematic investigations revealed a synergy between hierarchical pores and acidity: the hollow hierarchical pores enhance molecular transport, improving accessibility and utilization of acid sites, which collectively boost the catalytic performance. The catalyst also exhibited excellent stability over five cycles. Meanwhile, an integrated temperature‐controlled purification strategy enabled direct production of high‐purity melamine (98.3%). Reaction pathways were further elucidated by comprehensive analyses and DFT calculations. This work provides fundamental insights into hierarchical pores‐acidity synergy for the rational design of efficient zeolite catalysts.