Uniformly supported nanoparticles have been employed in various catalytic reactions. Recently, dry reforming of methane (DRM) has attracted much attention for reducing greenhouse gases. However, improving catalyst properties both in terms of syngas productivity and reaction stability against coke deposition is still a major issue. We report a new uniform Cs-promoted Ni/Al2O3 nanocatalyst with very high Ni loading and small particle sizes (ca. 5 nm), prepared via a facile melt infiltration route in an All-In-One automated apparatus designed for the synthesis of solid catalysts. The proposed nanocatalyst showed very high productivity for syngas as well as enhanced coke resistance, which enabled the reaction to proceed under extremely high space velocity conditions up to 180 NL gcat−1 h−1. The improved catalytic properties are also elucidated by computational studies.