Thermochemistry of Microporous and Mesoporous Materials

摘要

Liberation of ceramic science from the tyranny of hightemperature equilibrium thus is leading to new materials synthesized more quickly, at lower cost, and under enVironmentally more friendly conditions. There is, of course, a price to pay. First, the synthetic procedures are more complex than traditional “mix, grind, fire, and repeat” ceramic processing. Second, and more importantly, relatiVely little is known about the long-term stability in either a thermodynamic or a kinetic sense, of the materials formed, about their degradation during use, and about materials compatibility. Two examples of such problems are the potential corrosion of materials by ambient H2O and CO2 and the collapse to inactive phases of complex zeolitic and mesoporous catalysts under operating conditions. Chemical reactions in metastable materials are governed by an intertwined combination of thermodynamic driving forces and kinetic barriers. For this rich landscape of new materials, neither the depths of the valleys nor the heights of the mountains are known; indeed, one cannot even always tell which way is energetically downhill.