This study experimentally characterizes the motion of an artificial micro-scale swimmer that uses a chemical reaction catalyzed on its surface for autonomous propulsion. The swimmer is a polystyrene sphere coated on one side with platinum, which catalyzes the reduction of hydrogen peroxide to oxygen and water. The motion of the swimmer is analyzed as a function of hydrogen peroxide concentration. At short times, the swimmer exhibits directed motion with a velocity dependent on the concentration of fuel molecules. However, at longer times, the motion reverts to a random walk with a significantly enhanced diffusion coefficient. The results suggest strategies for designing artificial chemotactic systems. The directed propulsion of small-scale objects in water is challenging due to the low Reynolds number and Brownian motion. Common bacteria use non-time-reversible motion of flagella and a "run and tumble" strategy to navigate. One possibility for propulsion is non-reciprocal deformation strategies. Another is phoretic effects, where gradients of fields couple to surface properties to create slip velocity patterns. A particularly appealing strategy is chemical reactions, which have been used in experiments with platinum/gold nanorods and enzymes. The study realizes a scheme where a spherical particle has an asymmetric distribution of catalyst on its surface. The chemical reaction produces more products than reactants, leading to self-diffusiophoresis and propulsion. The experimentally realized swimmers are similar to this scheme, but the driving mechanism is different, involving electrochemical reactions. The study shows that the motion of the swimmer is characterized by a combination of directed and random motion. The results are consistent with theoretical predictions, with the rotational diffusion coefficient showing a moderate concentration dependence. The effective diffusion coefficient is significantly enhanced over the classical value. The study also shows that the propulsion velocity is proportional to the effective surface reaction rate, leading to a Michaelis-Menten behavior. The diffusion coefficient is largely independent of the presence of catalyst and hydrogen peroxide concentration. The rotational diffusion time decreases with increasing hydrogen peroxide concentration. The study concludes that spatially asymmetric catalysis at the surface of synthetic particles can lead to effective autonomous propulsion. At short times, the particles move in a directed manner, while at longer times, the motion becomes diffusive with an enhanced effective diffusion coefficient. The results provide insights into designing chemical locomotive systems and could inspire new directions for their implementation.This study experimentally characterizes the motion of an artificial micro-scale swimmer that uses a chemical reaction catalyzed on its surface for autonomous propulsion. The swimmer is a polystyrene sphere coated on one side with platinum, which catalyzes the reduction of hydrogen peroxide to oxygen and water. The motion of the swimmer is analyzed as a function of hydrogen peroxide concentration. At short times, the swimmer exhibits directed motion with a velocity dependent on the concentration of fuel molecules. However, at longer times, the motion reverts to a random walk with a significantly enhanced diffusion coefficient. The results suggest strategies for designing artificial chemotactic systems. The directed propulsion of small-scale objects in water is challenging due to the low Reynolds number and Brownian motion. Common bacteria use non-time-reversible motion of flagella and a "run and tumble" strategy to navigate. One possibility for propulsion is non-reciprocal deformation strategies. Another is phoretic effects, where gradients of fields couple to surface properties to create slip velocity patterns. A particularly appealing strategy is chemical reactions, which have been used in experiments with platinum/gold nanorods and enzymes. The study realizes a scheme where a spherical particle has an asymmetric distribution of catalyst on its surface. The chemical reaction produces more products than reactants, leading to self-diffusiophoresis and propulsion. The experimentally realized swimmers are similar to this scheme, but the driving mechanism is different, involving electrochemical reactions. The study shows that the motion of the swimmer is characterized by a combination of directed and random motion. The results are consistent with theoretical predictions, with the rotational diffusion coefficient showing a moderate concentration dependence. The effective diffusion coefficient is significantly enhanced over the classical value. The study also shows that the propulsion velocity is proportional to the effective surface reaction rate, leading to a Michaelis-Menten behavior. The diffusion coefficient is largely independent of the presence of catalyst and hydrogen peroxide concentration. The rotational diffusion time decreases with increasing hydrogen peroxide concentration. The study concludes that spatially asymmetric catalysis at the surface of synthetic particles can lead to effective autonomous propulsion. At short times, the particles move in a directed manner, while at longer times, the motion becomes diffusive with an enhanced effective diffusion coefficient. The results provide insights into designing chemical locomotive systems and could inspire new directions for their implementation.