Highly reliable 64-channel sequential and parallel tubular reactor for high-throughput screening of heterogeneous catalysts is constructed with stainless steel. In order to have a uniform flow rate at each channel, 64 capillaries are placed between the outlet of multiport valve and the inlet of each reactor. Flow rate can be controlled within +/- 1.5%. Flow distribution can be easily adjusted for sequential and parallel mode of operation. The reactor diameter is too big to have a uniform temperature distribution. Hence, the reactor body is separated into three radial zones and controlled independently with nine thermocouples. Temperature accuracy is +/- 0.5 degrees C at 300 degrees C and +/- 1 degrees C at 500 degrees C in sequential mode, while it is +/- 2.5 degrees C in the range of 250-500 degrees C in parallel mode. The temperature, flow rate, reaction sequence, and product analysis are controlled by LABVIEW (TM) software and monitored simultaneously with displaying a live graph. The accuracy in the conversion is +/- 2% at the level of 73% conversion when all reactors are loaded with same amount of catalyst. A quaternary catalyst library of 56 samples composed of Pt, Cu, Fe, and Co supported on AlSBA-15 (SBA-15 substituted with Al) are evaluated in the selective catalytic reduction of NO at various temperatures with our system. The most active compositions are rapidly screened at various temperatures. (c) 2005 American Institute of Physics.