Study on the thermal decomposition of a copper-containing hydrotalcite-like catalytic material

The hydrotalcite like compound Cu0.13Mg0.6Al10.27(OH)(2)(CO3)(0.135) . xH(2)O (CuHTlc) are synthesized by coprecipitation method and are characterized by XRD, DTA-TG, BET, TEM and Al-27 NIAS NMR. The results show that at relatively low calcination temperatures (below 300 degrees C), the layer structure of CuHTlc is retained, although partial dehydroxylation in addition to dehydration occurs. At 500 degrees C, the hydrotalcite structure is destroyed and MgO phase appears, the spinel phase forms with the further increase of calcination temperature. CuHTlc calcined ut 500 degrees C has the highest surface area (193m(2).g(-1)). When CuHTlc are calcined above 500 degrees C, the composition of resulting products is Cu0.13Mg0.6Al0.27O0.135, the equation of thermal decoposition of CuHTlc can be expressed as following: Cu0.13Mg0.6Al0.(27)(OH)(2)(CO3)(0.135) . xH(2)O --> Cu0.13Mg0.6Al0.27O0.135 + (1 + x)H2O + 0.135CO(2).