Idaho National Laboratory (INL) has unique capabilities to develop and evaluate heterogeneous catalysts for harsh environments, especially highly corrosive, high-temperature environments that exist in the sulfur-based thermochemical water splitting cycles. Developed as part of the Nuclear Hydrogen Program, INL capabilities include multiple corrosion resistant, high-temperature, fully automated systems with on-line product analysis. These systems were used to characterize catalytic activity and stability for the high-temperature sulfuric acid and hydroiodic acid decomposition reactions at industrially relevant conditions of temperatures, pressures and space velocities. INL capabilities were strengthened by collaborations with commercial catalyst manufacturer Johnson Matthey, National Laboratories (Sandia National Laboratory, Savannah River National Laboratory, and Pacific National Laboratory) and scale-up partner General Atomics (GA). INL's role in the Nuclear Hydrogen Program was to develop sulfur resistant catalysts and evaluate long term (1,000 hour) activity and stability. Characteristics were identified for low cost HI splitting catalysts to be used in scale-up studies. To date, no highly active catalysts have been proven to withstand the harsh sulfuric acid decomposition reaction at industrial reaction conditions for greater than 1,000 hours of operation, however, capabilities to develop active and stable bimetallic catalysts now reside at INL.