000131346 001__ 131346 000131346 005__ 20240207154753.0 000131346 0247_ $$2doi$$a10.1021/acscatal.1c01395 000131346 0248_ $$2sideral$$a135367 000131346 037__ $$aART-2021-135367 000131346 041__ $$aeng 000131346 100__ $$0(orcid)0000-0003-1115-6759$$aGeer, Ana M. 000131346 245__ $$aElectrocatalytic Water Oxidation by a Trinuclear Copper(II) Complex 000131346 260__ $$c2021 000131346 5060_ $$aAccess copy available to the general public$$fUnrestricted 000131346 5203_ $$aWe report a trinuclear copper(II) complex, [(DAM)Cu3(μ3-O)][Cl]4 (1, DAM = dodecaaza macrotetracycle), as a homogeneous electrocatalyst for water oxidation to dioxygen in phosphate-buffered solutions at pH 7.0, 8.1, and 11.5. Electrocatalytic water oxidation at pH 7 occurs at an overpotential of 550 mV with a turnover frequency of ∼19 s–1 at 1.5 V vs NHE. Controlled potential electrolysis (CPE) experiments at pH 11.5 over 3 h at 1.2 V and at pH 8.1 for 40 min at 1.37 V vs NHE confirm the evolution of dioxygen with Faradaic efficiencies of 81% and 45%, respectively. Rinse tests conducted after CPE studies provide evidence for the homogeneous nature of the catalysis. The linear dependence of the current density on the catalyst concentration indicates a likely first-order dependence on the Cu precatalyst 1, while kinetic isotope studies (H2O versus D2O) point to involvement of a proton in or preceding the rate-determining step. Rotating ring-disk electrode measurements at pH 8.1 and 11.2 show no evidence of H2O2 formation and support selectivity to form dioxygen. Freeze-quench electron paramagnetic resonance studies during electrolysis provide evidence for the formation of a molecular copper intermediate. Experimental and computational studies support a key role of the phosphate as an acceptor base. Moreover, density functional theory calculations highlight the importance of second-sphere interactions and the role of the nitrogen-based ligands to facilitate proton transfer processes. 000131346 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/ 000131346 590__ $$a13.7$$b2021 000131346 591__ $$aCHEMISTRY, PHYSICAL$$b19 / 165 = 0.115$$c2021$$dQ1$$eT1 000131346 592__ $$a4.202$$b2021 000131346 593__ $$aChemistry (miscellaneous)$$c2021$$dQ1 000131346 593__ $$aCatalysis$$c2021$$dQ1 000131346 594__ $$a20.8$$b2021 000131346 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000131346 700__ $$aMusgrave III, Charles 000131346 700__ $$aWebber, Christopher 000131346 700__ $$aNielsen, Robert J. 000131346 700__ $$aMcKeown, Bradley A. 000131346 700__ $$aLiu, Chang 000131346 700__ $$aSchleker, P. Philipp M. 000131346 700__ $$aJakes, Peter 000131346 700__ $$aJia, Xiaofan 000131346 700__ $$aDickie, Diane A. 000131346 700__ $$aGranwehr, Josef 000131346 700__ $$aZhang, Sen 000131346 700__ $$aMachan, Charles W. 000131346 700__ $$aGoddard, William A. 000131346 700__ $$aGunnoe, T. Brent 000131346 773__ $$g11, 12 (2021), 7223-7240$$pACS catal.$$tACS CATALYSIS$$x2155-5435 000131346 8564_ $$s1846672$$uhttps://zaguan.unizar.es/record/131346/files/texto_completo.pdf$$yPostprint 000131346 8564_ $$s2400696$$uhttps://zaguan.unizar.es/record/131346/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000131346 909CO $$ooai:zaguan.unizar.es:131346$$particulos$$pdriver 000131346 951__ $$a2024-02-07-14:41:34 000131346 980__ $$aARTICLE