Evidence for Quinone Redox Chemistry Mediating Daytime and Nighttime NO-to-HONO Conversion on Soil Surfaces.

Humic acid (HA) is thought to promote NO conversion to nitrous acid (HONO) on soil surfaces during the day. However, it has proven difficult to identify the reactive sites in natural HA substrates. The mechanism of NO reduction on soil surrogates composed of HA and clay minerals was studied by use of a coated-wall flow reactor and cavity-enhanced spectroscopy.

Electroreductive Remediation of Halogenated Environmental Pollutants.

Electrochemical reduction of halogenated organic compounds is gaining increasing attention as a strategy for the remediation of environmental pollutants. We begin this review by discussing key components (cells, electrodes, solvents, and electrolytes) in the design of a procedure for degrading a targeted pollutant, and we describe and contrast some experimental techniques used to explore and characterize the electrochemical behavior of that pollutant. Then, we describe how to probe various mechanistic features of the pertinent electrochemistry (including stepwise versus concerted carbon-halogen bond cleavage, identification of reaction intermediates, and elucidation of mechanisms).