固体渗硼提高煤基多孔炭抗氧化性

Doping of Boron into Coal-based Porous Carbons to Improve Oxidation Resistance

多孔炭在高温下易被氧化,限制了其在高温领域的应用。为了提高多孔炭高温下的抗氧化能力,分别以氧化硼、碳化硼为供硼剂对煤质多孔炭进行固体渗硼。采用X射线衍射、红外光谱、热重、扫描电镜及透射电镜对改性前后多孔炭样品进行了表征。结果表明,分别以碳化硼和氧化硼为渗硼剂的两种固体渗硼方法均能显著提高煤基多孔炭高温下的抗氧化性,氧化失重可由渗硼前的67.7%降低至16.8%。需要指出的是,不同渗硼剂的抗氧化性效果与温度有关。在较低温度下,氧化硼改性多孔炭的抗氧化性略优于碳化硼改性多孔炭,而在600℃以上高温时,碳化硼改性多孔炭的抗氧化性明显优于氧化硼改性多孔炭。

Porous carbons（PC） have been extensively used in variety of industries.However,their poor oxidation resistance,especially at high temperature（e.g.370℃）,has severely limited their applications.To improve the oxidation resistance of PC,solid-state B4C and B2O3 were introduced,separately,to coal-based PC by solid boron-doping.The samples,prior to and after the doping treatments,were systematically characterized by XRD,FTIR,TGA,SEM and TEM.Results revealed that the oxidation resistance of resulting PC was effectively improved by boron-doping.After boron-doping,the weight loss of PC was significantly decreased from 67.7% to 16.8%.It is noteworthy that the oxidation resistance of the modified PC depends on the used doping additives and specific applicable temperatures.Specifically,B4C doped PC showed better oxidation resistance than that of its B2O3 counterpart at 600℃.While at lower temperature,an opposite trend was observed.