Sorbents/catalysts based on Al2O3-supported CuO were prepd. by impregnation using a CuSO4 soln., activated under H2, and exposed to SO2 and O2. The subsequent redn. of those samples (before and after sulfation) was studied by temp.-programmed redn. (TPR) using H2 or CH4 as the reducing gas. The reaction products were analyzed by mass spectrometry. In addn., chem. anal. for Cu and sulfate, XPS, and Fourier transform IR analyses were carried out. Prior to sulfation, sulfate impregnated as CuSO4 is transferred to the Al2O3 to form Al2(SO4)3. The TPR profile then corresponds to the redn. of CuO or CuAl2O4, followed by the redn. of Al2(SO4)3. Any residual CuSO4 is reduced to CuS. After sulfation, the S-to-Cu ratio achieved was usually >2:1. In these circumstances the Cu was present as CuSO4. This compd. was reduced to form metallic Cu and SO2, but some CuS also formed. At higher temps., Al2(SO4)3 was reduced as well as the CuS formed at the lower temps. CH4 is a less powerful reducing agent than H2, but its utilization avoided the formation of CuS. [on SciFinder(R)]
Temperature-programmed reduction and x-ray photoelectron spectroscopy of copper oxide on alumina following exposure to sulfur dioxide and oxygen
CENTI, Gabriele;
1991-01-01
Abstract
Sorbents/catalysts based on Al2O3-supported CuO were prepd. by impregnation using a CuSO4 soln., activated under H2, and exposed to SO2 and O2. The subsequent redn. of those samples (before and after sulfation) was studied by temp.-programmed redn. (TPR) using H2 or CH4 as the reducing gas. The reaction products were analyzed by mass spectrometry. In addn., chem. anal. for Cu and sulfate, XPS, and Fourier transform IR analyses were carried out. Prior to sulfation, sulfate impregnated as CuSO4 is transferred to the Al2O3 to form Al2(SO4)3. The TPR profile then corresponds to the redn. of CuO or CuAl2O4, followed by the redn. of Al2(SO4)3. Any residual CuSO4 is reduced to CuS. After sulfation, the S-to-Cu ratio achieved was usually >2:1. In these circumstances the Cu was present as CuSO4. This compd. was reduced to form metallic Cu and SO2, but some CuS also formed. At higher temps., Al2(SO4)3 was reduced as well as the CuS formed at the lower temps. CH4 is a less powerful reducing agent than H2, but its utilization avoided the formation of CuS. [on SciFinder(R)]Pubblicazioni consigliate
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