Oscillatory behavior and anomalous heat evolution in recombination of H2 and O2 on Pd-based catalysts
- Industrial & Engineering Chemistry Research - American Chemical Society - June 29, 2015
Gas flow-through microcalorimetry has been applied to study the Pd/Al2O3 type catalysts in the exothermic hydrogen recombination process: H2 + O2 H2O, in view of the potential application in the passive autocatalytic recombination (PAR) technology. The flow mode experiments revealed thermokinetic oscillations, i.e., the oscillatory rate of heat evolution accompanying the process and the corresponding oscillations in the differential heat of process, in sync with oscillatory conversion of hydrogen. Mathematical chaos in the rate of heat evolution has been confirmed. In the outburst of quasiperiodic oscillations of large amplitude, the instances of differential heats as high as 700 kJ/mol H2 have been detected, exceeding the heat of water formation (242 kJ/mol H2) by a factor of nearly three. Another occurrence of anomalously high thermal effects has been measured in calorimetric oxygen titration using 0.09 μmol pulses of O2 injected onto hydrogen- or deuterium-saturated catalysts, including 2%Pd/Al2O3, 5%Pd/Al2O3 and 2%PdAu/Al2O3. Repeatedly, the saturation/oxidation cycles showed the heat evolutions in certain individual O2 pulses as high as 1100 kJ/mol O2, i.e., 550 kJ/mol H2, again twice as much as the heat of water formation. It has been pointed out that it seems prudent for the PAR technologists to assume a much larger rate of heat evolution than those calculated on the basis of a standard thermodynamic value of the heat of water formation, in order to account for the possibility of large thermokinetic oscillation occasionally appearing in the recombination process of hydrogen. A possible relation of the anomalous heat evolution to an inadvertent occurrence of low energy nuclear reaction (LENR) phenomena is also briefly considered.
PDF document is available after free registration with ACS
Short Extract -
"There is currently no satisfactory explanation for the abnormally high thermal effects in the H2
+ O2 recombination reported here, but it may be suggested that the hydrogen-related anomalous
heat evolutions may be falling into the same category with the low energy nuclear reaction
phenomena (LENR). In view of the fact, that the PARs are intended to be used in nuclear
reactors as crucial safety devises, a possibility of uncontrollable heat evolutions caused by these
very devices themselves calls for a special consideration.
4.3. A danger of LENR occurrence. It is usual to view the [lexicon]low energy nuclear reactions[/lexicon]..."
(LENR) as a revolutionary new energy source, but they may also be viewed as posing a danger,