ABSTRACT The method of Sample Controlled Temperature (SCT) implies to control the temperature in such a way that the reaction rate follows a trend previously selected by the user. In the most common SCT method, the reaction rate is maintained constant all over the process. This control is achieved by means of a feedback system using an experimental signal (digital or analogical output) directly proportional to the reaction rate. This signal is used for controlling the temperature in such a way that the reaction rate remains constant all over the process at a value previously selected by the user. Experiments could be performed under vacuum, where the output signal of the pressure gauge (Penning, Pirani or Mass spectrometer) is used as monitoring signal and by means of a proper control of the pumping rate it is possible to independently select both a constant reaction rate and a constant residual pressure in the close vicinity of the sample. Additionally, it can work under flow of gases using chatarometers, IR detectors, electrochemical sensors, etc, to monitor the evolution of the reaction. This method has been successfully applied to the design of materials with controlled texture and structure. Thus, catalyst and catalyst related materials with tailored shape and porosity has been prepared from the thermal transformation of precursors under controlled reaction rate and partial pressure of the gases generated in the reaction. Moreover, the SCT method present significant advantages over the conventional procedures for the characterization of thermal desorption and redox reactions of catalysts. The literature on the applications of SCT method to both the synthesis of catalysts with controlled texture and structure and the characterization of catalysts is reviewed. Advantages of the SCT methods for performing kinetic analysis of solid-state reactions of interest in catalysis are also discussed.
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