Thermodynamics of the system Zr-B-H-Cl. A contribution at low temperature

A thermodynamic study of the Zr-B-H-Cl system was made at low temperature (800 to 1500K) and low pressure (1 to 100 mbar) by minimising of the total Gibbs free energy of the system. The Zr-B phase-diagrams showed that ZrB2 is the main solid product formed. The ZrB2 yield can reach 100% under conditions of elevated temperature, high H2 concentrations, and at low pressures. At low H2 concentration, the addition of helium had the same effect on the system as a reduction of the systemʹs total pressure. The analysis showed that the system is controlled by the formation of an intermediate species resulting from the reaction of H2 with BC13.