运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组...运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组分 La Co O3反应生成硫酸镧和氧化亚钴 ,而在催化剂膜层内部则生成硫酸镧、亚硫酸镧及氧化亚钴 . SO2 对活性组分层的侵入及硫与 La Co O3活性组分的反应破坏了催化剂的钙钛矿结构 ,使得催化剂彻底中毒 .当中毒温度较低及中毒时间较短时 ,硫在膜层中呈峰形分布 ,其浓度随中毒温度及时间的增加而增加 .随中毒温度的升高及中毒时间的增长 ,由于亚硫酸盐的分解作用 ,S在活性层中的浓度反而降低 ,中毒深度则继续增加 .展开更多
In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and...In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and MoO 3 TiO 2.The results showed that SO 2- 4 MoO 3 TiO 2 had better catalytic performance than SO 2- 4 TiO 2 and MoO 3 TiO 2.There was evident coordination between MoO 3 and SO 2- 4 when they coexisted on TiO 2.展开更多
The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\...The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\-3 as a monolayer and the dispersion threshold is 0.31\[\%m\%(K\-2CO\-3)/\%m\%(\%γ\%\|Al\-2O\-3), \%m\%/g\], which is close to the theoretical value calculated by assuming a bidentate vertical dispersion model of CO\-2 on the \%γ\%\|Al\-2O\-3 surface . The SO\-2 adsorption\|capacity on K\-2CO\-3/\%γ\%\|Al\-2O\-3 sample increases with the K\-2CO\-3 loading and reaches an extremum at its threshold. The adsorbent conversion of K\-2CO\-3/\%γ\%\|Al\-2O\-3 at the threshold is up to 72%. When the loading is higher than the threshold, the SO\-2 adsorption capacity decreases at first, then increases again. This phenomenon is caused by the reaction between SO\-2 and the bulk phase of K\-2CO\-3 crystallites. The sample decreases with the loading, and the sample with \{0.10\}\[\%m\%(K\-2CO\-3)/\%m(γ\%\|Al\-2O\-3), \%m\%/g\] loading shows the highest regeneration percentage of 63%. Compared with Na\-2CO\-3/\%γ\%\|Al\-2O\-3, K\-2CO\-3/\%γ\%\|Al\-2O\-3 might have some advantages.展开更多
The catalytic performance of sulfided Mn/Al 2O 3 and Cu-Mn/Al 2O 3 catalysts for the ammonia decomposition has been studied by using a fixed-bed flow apparatus. It is found that the addition of copper component to Mn/...The catalytic performance of sulfided Mn/Al 2O 3 and Cu-Mn/Al 2O 3 catalysts for the ammonia decomposition has been studied by using a fixed-bed flow apparatus. It is found that the addition of copper component to Mn/Al 2O 3 catalyst can increase its catalytic activity for ammonia decomposition. The results of TPR indicate that the existence of copper component significantly improves the reduction of catalysts, which is beneficial to form active metal sulfide phase to catalyze the reduction of SO 2 to H 2S by hydrogen. X-ray diffraction results reveal that the Cu-Mn/Al 2O 3 catalyst (n Cu /n Mn =0.4) contains a CuMn 2O 4 phase before reaction, and displays MnS peaks after reaction.展开更多
文摘运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组分 La Co O3反应生成硫酸镧和氧化亚钴 ,而在催化剂膜层内部则生成硫酸镧、亚硫酸镧及氧化亚钴 . SO2 对活性组分层的侵入及硫与 La Co O3活性组分的反应破坏了催化剂的钙钛矿结构 ,使得催化剂彻底中毒 .当中毒温度较低及中毒时间较短时 ,硫在膜层中呈峰形分布 ,其浓度随中毒温度及时间的增加而增加 .随中毒温度的升高及中毒时间的增长 ,由于亚硫酸盐的分解作用 ,S在活性层中的浓度反而降低 ,中毒深度则继续增加 .
文摘In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and MoO 3 TiO 2.The results showed that SO 2- 4 MoO 3 TiO 2 had better catalytic performance than SO 2- 4 TiO 2 and MoO 3 TiO 2.There was evident coordination between MoO 3 and SO 2- 4 when they coexisted on TiO 2.
文摘The dispersion of K\-2CO\-3 on \%γ\%\|Al\-2O\-3 and the adsorption performance of K\-2CO\-3/\%γ\%\|Al\-2O\-3 to SO\-2 are investigated.The results show that K\-2CO\-3 can disperse onto the surface of \%γ\%\|Al\-2O\-3 as a monolayer and the dispersion threshold is 0.31\[\%m\%(K\-2CO\-3)/\%m\%(\%γ\%\|Al\-2O\-3), \%m\%/g\], which is close to the theoretical value calculated by assuming a bidentate vertical dispersion model of CO\-2 on the \%γ\%\|Al\-2O\-3 surface . The SO\-2 adsorption\|capacity on K\-2CO\-3/\%γ\%\|Al\-2O\-3 sample increases with the K\-2CO\-3 loading and reaches an extremum at its threshold. The adsorbent conversion of K\-2CO\-3/\%γ\%\|Al\-2O\-3 at the threshold is up to 72%. When the loading is higher than the threshold, the SO\-2 adsorption capacity decreases at first, then increases again. This phenomenon is caused by the reaction between SO\-2 and the bulk phase of K\-2CO\-3 crystallites. The sample decreases with the loading, and the sample with \{0.10\}\[\%m\%(K\-2CO\-3)/\%m(γ\%\|Al\-2O\-3), \%m\%/g\] loading shows the highest regeneration percentage of 63%. Compared with Na\-2CO\-3/\%γ\%\|Al\-2O\-3, K\-2CO\-3/\%γ\%\|Al\-2O\-3 might have some advantages.
文摘The catalytic performance of sulfided Mn/Al 2O 3 and Cu-Mn/Al 2O 3 catalysts for the ammonia decomposition has been studied by using a fixed-bed flow apparatus. It is found that the addition of copper component to Mn/Al 2O 3 catalyst can increase its catalytic activity for ammonia decomposition. The results of TPR indicate that the existence of copper component significantly improves the reduction of catalysts, which is beneficial to form active metal sulfide phase to catalyze the reduction of SO 2 to H 2S by hydrogen. X-ray diffraction results reveal that the Cu-Mn/Al 2O 3 catalyst (n Cu /n Mn =0.4) contains a CuMn 2O 4 phase before reaction, and displays MnS peaks after reaction.
