论文部分内容阅读
The use of non-equilibrium plasmas for the synthesis of heterogeneous catalysts is a field that has not been explored intensively.The main reasons for the recent increase of research activity in this field are related to the advantages that go with the technique of plasma enhanced chemical vapor deposition(PECVD).The most principal of these advantages are the possibility to avoid the use of environmentally harmful solvents and the one-step nature of the procedure,making it very time and labor efficient.Non-equilibrium plasma technology,more in particular dielectric barrier discharge(DBD) technology,has been applied in this work for the synthesis of hybrid tin-silicate materials to be used as a heterogeneous catalyst in the isomerization of glucose into fructose.Atomizers,innovative devices which make it possible to inject nanosized precursor liquids into the plasma zone,are used instead of applying vapor phase techniques,where the amount of precursor is limited by the vapor pressure of the liquid.A design of experiments approach has been employed to investigate the effect of the plasma parameters, namely gas flow,frequency and power density,on the catalytic properties of the catalysts within a well-defined parameter field.It has been found that indeed these parameters,together with the molar ratio of Si/Sn,have an important influence on the activity,selectivity,and thus yield of the produced chemicals.
The use of non-equilibrium plasmas for the synthesis of heterogeneous catalysts is a field that has not been explored intensively. The main reasons for the recent increase of research activity in this field are related to the advantages that go with the technique of plasma enhanced chemical vapor deposition (PECVD). the most principal of these advantages are the possibility to avoid the use of environmentally harmful solvents and the one-step nature of the procedure, making it very time and labor efficient. Non-equilibrium plasma technology, more particularly dielectric barrier discharge (DBD) technology, has been applied in this work for the synthesis of hybrid tin-silicate materials to be used as a heterogeneous catalyst in the isomerization of glucose into fructose. Atomizers, innovative devices which make it possible to inject nanosized precursor liquids into the plasma zone, are used instead of applying vapor phase techniques, where the amount of precursor is limited by the vapor pressure of the liquid. A design of experiments approach has been employed to investigate the effect of the plasma parameters, namely gas flow, frequency and power density, on the catalytic properties of the catalysts within a well-defined parameter field. It has been found that that indeed these parameters, together with the molar ratio of Si / Sn, have an important influence on the activity, selectivity, and thus yield of the produced chemicals.