Remarks on catalytic reduction of CO2, H+ and H2 by monovalent Ni.
Prompted by catalysis of CO2 electroreduction by a tetraazamacrocyclic Ni(i)(cyclam) complex (cyclam = 1,4,8,11-tetraazacyclotetradecane), we examine theoretically the possibility of H2 reduction by this molecule. We show that the process 2 Ni(i) + H2 --> 2 [Ni(ii)(H-)] is thermodynamically facile, and that H2 could be reduced by a binuclear Ni(i) complex in two concerted 1e- processes. Our calculations also indicate that hydride complexes of Ni(iii)(cyclam) are significantly unstable thermodynamically and therefore they are unlikely to serve as intermediates in process of H2 evolution from water.
Grochala
Wojciech
W
Interdisciplinary Center for Mathematical and Computational Modeling, University of Warsaw, Pawińskiego 5a, 02106 Warsaw, Poland. wg22@cornell.edu