The anodic conversion of diphenylacetaldehyde to benzophenone in air is shown to take place by two paths when not carried out under an inert atmosphere. One path is electrochemical, proceeding in two steps via 2-hydroxydiphenylacetaldehyde as an intermediate. The other path involves direct conversion of the aldehyde to benzophenone by reaction with oxygen. Labeling studies are used to substantiate the proposed mechanisms and quantum chemical computations are used to examine the feasibility of several possible mechanisms for the aerobic oxidation of diphenylacetaldehyde. (C) 2012 The Electrochemical Society. [DOI:10.1149/2.039210jes] All rights reserved.