Role of Multiple Vanadium Centers on Redox Buffering and Rates of Polyvanadomolybdate-Cu(II)-Catalyzed Aerobic Oxidations.

A recent report established that the tetrabutylammonium (TBA) salt of hexavanadopolymolybdate TBAH[PMoVO] () serves as the redox buffer with Cu(II) as a co-catalyst for aerobic deodorization of thiols in acetonitrile. Here, we document the profound impact of vanadium atom number ( = 0-4 and 6) in TBA salts of PVMoO () on this multicomponent catalytic system. The cyclic voltammetric peaks from 0 to -2000 mV vs Fc/Fc under catalytic conditions (acetonitrile, ambient T) are assigned and clarify that the redox buffering capability of the /Cu catalytic system derives from the number of steps, the number of electrons transferred each step, and the potential ranges of each step.

Catalytic System for Aerobic Oxidation That Simultaneously Functions as Its Own Redox Buffer.

The control of the solution electrochemical potential as well as pH impacts products in redox reactions, but the former gets far less attention. Redox buffers facilitate the maintenance of potentials and have been noted in diverse cases, but they have not been a component of catalytic systems. We report a catalytic system that contains its own built-in redox buffer.

Structurally Precise Two-Transition-Metal Water Oxidation Catalysts: Quantifying Adjacent 3d Metals by Synchrotron X-Radiation Anomalous Dispersion Scattering.

Mixed 3d metal oxides are some of the most promising water oxidation catalysts (WOCs), but it is very difficult to know the locations and percent occupancies of different 3d metals in these heterogeneous catalysts. Without such information, it is hard to quantify catalysis, stability, and other properties of the WOC as a function of the catalyst active site structure. This study combines the site selective synthesis of a homogeneous WOC with two adjacent 3d metals, [CoNi(PWO)] () as a tractable molecular model for CoNi oxide, with the use of multiwavelength synchrotron X-radiation anomalous dispersion scattering (synchrotron XRAS) that quantifies both the location and percent occupancy of Co (∼97% outer-central-belt positions only) and Ni (∼97% inner-central-belt positions only) in .

A solvent-free solid catalyst for the selective and color-indicating ambient-air removal of sulfur mustard.

Bis(2-chloroethyl) sulfide or sulfur mustard (HD) is one of the highest-tonnage chemical warfare agents and one that is highly persistent in the environment. For decontamination, selective oxidation of HD to the substantially less toxic sulfoxide is crucial. We report here a solvent-free, solid, robust catalyst comprising hydrophobic salts of tribromide and nitrate, copper(II) nitrate hydrate, and a solid acid (Nafion) for selective sulfoxidation using only ambient air at room temperature.