Non-intrusive temperature measurement of the components of a working catalyst by neutron resonance radiography

Neutron resonance radiography is the first practical method capable of detecting microscopic temperature inhomogeneities within a catalyst under realistic operating conditions. The method is non-intrusive and can be used with powdered or pelleted catalysts in standard stainless steel reactors. The neutron/nuclei interaction yields a resonance absorption spectrum characteristic of the element involved and the temperature can be determined directly from thermal broadening of the spectrum. A 14% Pt/samaria catalyst was used for CO hydrogenation under conditions which produced a controlled exotherm of between 20 and 50 ° C. The thermal broadening of the platinum resonance peak at 11.9 eV and the samarium resonance peak at 3.4 eV provided a measure of the temperature of the metal and support phases. Typical values obtained for the metal and support temperature were 420±6 ° C and 424±2 ° C respectively compared to a thermocouple reading of 424±1 ° C.