Simultaneous recovery of carbon and sulfur resources from reduction of CO_2 with H_2S using catalysts

An approach to the simultaneous reclamation of carbon and sulfur resources from CO2 and H2S has been proposed and effectively implemented with the aid of catalysts. A brief thermodynamic study reveals the potential of direct reduction of CO2 with H2S（15：15 mol% balanced with N2） for selective production of CO and elemental sulfur. The experiments carried out in a fixed-bed flow reactor over the temperature range of 400–800 °C give evidence of the importance of the employment of catalysts. Both the conversions of the reactants and the selectivities of the target products can be substantially promoted over most catalysts studied. Nevertheless, little difference appears among their catalytic performance. The results also prove that the presence of CO2 can remarkably enhance H2S conversion and the sulfur yield in comparison with H2S direct decomposition. A longtime reaction test on Mg O catalyst manifests its superior durability at high temperature（700 °C） and huge gas hourly space velocity（100,000 h-1）. Free radicals initiated by catalysts are supposed to dominate the reactions between CO2 and H2S.

Simultaneous Similarity Reductions for a Pair of Matrices to Condensed Forms

We present simultaneous reduction algorithms for two(nonsymmetric)matrices A and B to upper Hessenberg and lower Hessenberg forms,respectively.One is through the simultaneous similarity reduction and the other is through a Lanczos–Arnoldi-type iteration.The algorithm that uses the Lanczos–Arnoldi-type iteration can be considered as a generalization of both the nonsymmetric Lanczos algorithm and the standard Arnoldi algorithm.We shall also apply our reduction to construct a model reduction for certain kind second-order single-input single-output system.It is proved that the model reduction has the desirable moment matching property.

Electrochemically Reduced Graphene Oxide as Modified Electrode Material for Determination of Dihydroxybenzenes

A simple and green method was introduced to fabricate the electrochemical sensor based on the electrochemically reduced graphene oxide（ERGO） modified electrode. It was found that the ERGO modified electrode exhibited an excellent catalytic activity toward the oxidation of dihydroxybenzenes isomers. Under the optimum conditions, in the simultaneous determination of the dihydroxybenzene isomers, the currents were linear with the concentrations of the isomers from 5 to 550 μmol/L for hydroquinone（HQ）, from 6 to 400 μmol/L for catechol（CT） and from 5 to 350 μmol/L for resorcinol（RS）, respectively. In addition, the proposed sensor has good stability and reproducibility. The developed method has been applied to the simultaneous determination of dihydroxybenzene isomers in real samples with a satisfactory recovery from 98% to 103%.