High-throughput operando-ready X-ray absorption spectroscopy flow reactor cell for powder samples.

A high-throughput, operando-ready X-ray absorption spectroscopy catalytic reaction cell consisting of 4 parallel reactors was designed to collect X-ray absorption near edge structure and extended fine structure spectra under reaction conditions. The cell is capable of operating at temperatures from ambient conditions up to 773 K and pressures from ambient to 2 MPa in a variety of gas environments. The cell design is mechanically simple, and programmable operation at beamline 8-ID (NSLS-II, Brookhaven National Laboratory) makes it straightforward to use.

Mechanistic Studies of Single-Step Styrene Production Using a Rhodium(I) Catalyst.

The direct and single-step conversion of benzene, ethylene, and a Cu(II) oxidant to styrene using the Rh(I) catalyst (DAB)Rh(TFA)(η-CH) [DAB = N,N'-bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA = trifluoroacetate] has been reported to give quantitative yields (with Cu(II) as the limiting reagent) and selectivity combined with turnover numbers >800. This report details mechanistic studies of this catalytic process using a combined experimental and computational approach. Examining catalysis with the complex (DAB)Rh(OAc)(η-CH) shows that the reaction rate has a dependence on catalyst concentration between first- and half-order that varies with both temperature and ethylene concentration, a first-order dependence on ethylene concentration with saturation at higher concentrations of ethylene, and a zero-order dependence on the concentration of Cu(II) oxidant.