Linear Adsorption Enables NO Selective Electroreduction to Hydroxylamine on Single Co Sites

Abstract

Hydroxylamine (NH 2 OH), a vital industrial feedstock, is presently synthesized under harsh conditions with serious environmental and energy concerns. Electrocatalytic nitric oxide (NO) reduction is attractive for the production of hydroxylamine under ambient conditions. However, hydroxylamine selectivity is limited by the competitive reaction of ammonia production. Herein, we regulate the adsorption configuration of NO by adjusting the atomic structure of catalysts to control the product selectivity. Co single-atom catalysts show state-of-the-art NH 2 OH selectivity from NO electroreduction under neutral conditions (FE NH 2 OH : 81.3 %), while Co nanoparticles are inclined to generate ammonia (FE NH 3 : 92.3 %). A series of in situ characterizations and theoretical simulations unveil that linear adsorption of NO on isolated Co sites enables hydroxylamine formation and bridge adsorption of NO on adjacent Co sites induces the production of ammonia.

Electrocatalytic Synthesis of Pyridine Oximes using in Situ Generated NH2OH from NO species on Nanofiber Membranes Derived from NH2‐MIL‐53(Al)

“…These results demonstrate the superiority of MOF‐based derivative, which maybe reason from the Al−O unsaturated sites to interreact with NO and the channel for mass transfer originated from MOF. In the process of NORR, NH 2 OH and NH 3 are the major product according to the previous work [10b,24] . To Figure out the catalytic reaction pathway, NH 2 OH or NH 3 was separately added into 2‐formylpyridine solution (Figure S35), 2‐pyridinealdoxime was observed only in the present of NH 2 OH, indicating NH 2 OH is the actively nucleophilic intermediate rather than NH 3 , and the formation of 2‐pyridinealdoxime from 2‐formylpyridine and NH 2 OH is spontaneous.…”

Electrocatalytic Systems for NOx Valorization in Organonitrogen Synthesis

“…For hydroxylamine, it is necessary to weaken the adsorption of NO on the catalyst surface to avoid NÀ O breaking. For instance, Zhang group [20] designed and prepared Co single-atom catalysts(Co SACs) and Co nanoparticle catalysts (Co NPs), realizing selective electroreduction of NO to NH 2 OH or NH 3 by adjusting the NO adsorption configuration. In the electrocatalytic process, Co SACs tended to linearly adsorb with NO, maintaining the NÀ O bonds during hydrogenation, resulting in generating NH 2 OH with high FE (81.3 %); while NO was adsorbed by bridge on Co NPs, which weakened and broken the NÀ O bond during hydrogenation and selectively generation of NH 3 (FE 92.3 %).…”

Electrochemical Reversible Reforming between Ethylamine and Acetonitrile on Heterostructured Pd‐Ni(OH)2 Nanosheets

“…[1][2][3][4][5][6][7] Currently, there are two main aspects of electrochemical synthesis: electrochemical reduction and electrochemical oxidation. Electrochemical reduction synthesis is mainly focused on hydrogenation of unsaturated bonds in substrate molecules, including CO 2 reduction, [4,8,9] NOx species reduction, [2,[10][11][12][13][14] acetylene reduction [15,16] and unsaturated CÀ N bonds reduction. [17][18][19][20] On the other hand, electrochemical oxidation synthesis involves partial oxidation of small molecules and selective dehydrogenation.…”