A high-throughput screening (HTS) reactor for high-pressure oxidative reforming of methane in a direct reaction route was developed. With a combination of catalyst preparation by a split-and-pool method and HTS, Ni-K/alpha-Al(2)O(3) catalyst was found to show high activity under 1 MPa at 650 degrees C with high selectivity even when O(2) conversion is less than 100%. The HTS reactor required a new simple syngas detector operable under high pressure because the number of parallel reactor is limited when equipped with the conventional detection system. The complexity of the pressure reducing unit is the main reason of the limitation. Reduction of metal oxide accompanied with the color change was applied to the detection system. Copper oxide was supported on the filter disk made of alumina, and the filter was placed underneath the catalyst bed. After the methane was oxidatively reformed under 1 MPa at 650 degrees C, color change of spots from dark brown to light brown was observed just under the catalyst which produced hydrogen. Color change of the disk can be used to detect hydrogen formation from the reforming catalyst under pressure.