Chemical fertilizer industry is of great importance to agricultural developments.Urea (CO(NH2)2),which was firstly discovered by Hilaire Rouelle in 1773,is the most widely used chemical fertilizers in the world [1].Up to now,urea still represents the solid nitrogen fertilizer with the highest nitrogen content.The synthesis of urea is therefore closely related to the fertilizer production and very important in the synthetic chemistry.The modern ammonia synthesis industry has laid a foundation for the large-scale artificial synthesis of urea.However,in this route,urea is typically synthesized from the Ostwald post-process of ammonia,which is produced based on the Haber-Bosch process at high temperatures and pressures.The harsh reaction conditions and the consumption of hydrogen in a large quantity set a huge obstacle for the green and sustainable development of urea manufacture [2].