A novel reactor for accelerated screening of gas-phase heterogeneous catalysts is described. It provides a first level of catalyst screening so that the higher-ranking candidates can be subjected to more detailed performance evaluation using a parallel fixed-bed microreactor system. The system allows 16 granular heterogeneous catalyst samples to be independently exposed to a constant flow rate of a multi-component reaction gas mixture while the temperature of an individual sample holder is ramped over a user-specified temperature range. Operationally, it is a type of serial temperature-programmed reaction evaluation system. The catalysts are contained in equally spaced holes on the periphery of circular wheel that rotates into position. The reaction gas fluidic inlet and outlet couplings engage the circular openings through pivoting arms equipped with soft gas-tight seals. Product analysis is performed using a scanning mass spectrometer. The unit is fully automated for unattended, safe operation. To demonstrate the system operation and illustrate the key features, catalyst screening data are provided for the partial oxidation of 1,3-butadiene to furan, which is an intermediate step in the manufacture of monomers used for the manufacture of stretch polymers and other commercial products. Comparisons to screening data from a parallel fixed-bed microreactor system are also provided. It is shown that relative catalyst rankings using common measures of performance from the two independent systems are in good agreement, which validates the utility of the system as an accelerated screening tool.