A high-temperature differential microcalorimeter for the study of gas adsorption on high-surface-area materials is designed and constructed. The system is designed to operate at temperature up to 625 K, using special materials for this propose. For operation below 450 K, the pressure-gauge heads will be inside the controlled-temperature region, as with present near-ambient designs; for operation in the "high- temperature" region (450-625 K), the system can be reconfigured to place the pressure gauges outside the high- temperature zone. The system will be used in combination with catalytic tests to correlate carbon surface chemistry with the catalytic behavior of carbon-supported metal catalysts, including iron-containing bimetallics. It will also be used in studies of diamond powder and of nanoparticles of silicon nitride.
