Polyoxometalate Confined Synthesis of BiVO Nanocluster for Urea Production with Remarkable O/N Tolerance.

Urea electrosynthesis from flue gas and NO under operating conditions represents a promising alternative technology to traditional energy-intensive industrial process. Herein, we explore a polyoxometalate confined synthesis strategy to prepare ultrafine BiVO nanocluster by pre-incorporating [VO] into NH-MIL-101-Al (MIL) framework. The resulting BiVO@MIL-n can efficiently drive co-reduction of NO and CO to urea. A record urea yield of 63.4 mmol h g was achieved under CO/O mixed gases (33 % O) atmosphere, and comparable performance can be obtained by feeding flue gas, demonstrating remarkable O/N tolerance and potential feasibility for urea production under operating conditions. Systematic investigations revealed that MIL carrier with -NH group can enrich CO, and BiVO nanocluster can reduce both NO and CO to ensure efficient urea synthesis even in the presence of O. This work demonstrates the key role of in situ growth of BiVO nanocluster within a NH-framework in facilitating urea electrosynthesis with exceptional tolerance to O/N.