Electrochemical water oxidation is a major focus of solar energy conversion efforts. A new laboratory experiment has been developed that utilizes real-time, hands-on research to discover catalysts for solar energy conversion. The HARPOON, or Heterogeneous Anodes Rapidly Perused for Oxygen Overpotential Neutralization, experiment allows an array of mixed-metal oxide compositions to be analyzed in parallel to test their activity as water oxidation catalysts. Students create unique combinations of mixed-metal oxide materials, which are then analyzed utilizing a simple, inexpensive system that detects the amount of oxygen evolved during electrolysis. This experiment has the flexibility to be implemented at a variety of educational levels with the depth and breadth of the material covered accordingly. Concepts such as stoichiometry, materials, solutions, and fluorescence can be emphasized, while the research-like experience strengthens students' independence, critical-thinking skills, and excitement for science. An online questionnaire was developed to measure various effects of the experiment on students, including learning gains, attitudes toward chemistry, and motivation to pursue a career in scientific research. The assessment results indicate positive gains for students in their understanding of the social nature of scientific work, scientific literacy, and interest in pursuing additional research opportunities.