摘要
使用原位穆斯堡尔谱考察了非担载铁-锰氧化物和铁-锰/活性炭(Fe-Mn/AC)催化剂在不同温度下的还原。还原前Fe-Mn/AC催化剂中存在的为超顺磁α-(Fe_1-_xMn_x)_2O_3和没有充分脱水的铁-锰氧化物。铁的还原同时受铁-锰和铁-活性炭相互作用的影响,载体活性炭使F^(3+)相对稳定而难以还原,锰则促进铁还原到Fe^(2+)并形成相对稳定的FeO-MnO固溶体而难以还原到Fe^0。对4%Mn-8%Fe/AC催化剂,即使在500℃氢气中处理,仍有相当数量的Fe^(3+)和Fe^(2+)不能还原。
The reduction of unsupported Fe-Mn oxide and an activated carbon (AC) supported Fe-Mn catalyst in H_2 at different temperatures has been investigated with in situ Mossbauer spectroscopy. Before reduction, superparamagnetic α-(Fe_(1-x)Mn_x)_2O_3 and hydrated Fe-Mn oxide exist in the Fe-Mn/AC catalyst which is dried at 120℃. The reduction of iron species in the Fe-Mn catalyst is affected by interactions between iron and the AC support and between iron and manganese. The AC support stabilizes Fe^(3+) and retards the reduction nf Fe^(3+), whereas manganese promotes the reduction of Fe^(3+) to Fe^(2+) forming。FeO-MnO solid solution which is stableagainst further reduction to Fe°. So, even after reduction in H_2 at 500℃, there will still be some Fe^(3+) and Fe^(2+) unreduced in the 4%Mn-8%Fe/AC catalyst.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1991年第2期108-113,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金
关键词
锰
锰
活性炭
催化剂
还原
iron manganese/activated carbon catalysts
reduction
mossbauer spectroscopy
