Regulating Reconstruction-Engineered Active Sites for Accelerated Electrocatalytic Conversion of Urea.
Angew Chem Int Ed Engl
; : e202407038, 2024 Jun 13.
Article
in En
| MEDLINE
| ID: mdl-38871655
ABSTRACT
Reconstruction-engineered electrocatalysts with enriched high active Ni species for urea oxidation reaction (UOR) have recently become promising candidates for energy conversion. However, to inhibit the over-oxidation of urea brought by the high valence state of Ni, tremendous efforts are devoted to obtaining low-value products of nitrogen gas to avoid toxic nitrite formation, undesirably causing inefficient utilization of the nitrogen cycle. Herein, we proposed a mediation engineering strategy to significantly boost high-value nitrite formation to help close a loop for the employment of a nitrogen economy. Specifically, platinum-loaded nickel phosphides (Pt-Ni2P) catalysts exhibit a promising nitrite production rate (0.82â
mol kWh-1 cm-2), high stability over 66â
h of Zn-urea-air battery operation, and 135â
h of co-production of nitrite and hydrogen under 200â
mA cm-2 in a zero-gap membrane electrode assembly (MEA) system. The in situ spectroscopic characterizations and computational calculations demonstrated that the urea oxidation kinetics is facilitated by enriched dynamic Ni3+ active sites, thus augmenting the "cyanate" UOR pathway. The C-N cleavage was further verified as the rate-determining step for nitrite generation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
Year:
2024
Type:
Article
Affiliation country:
United kingdom