Yixin HUA
,
Yong YANG
,
Fuliang ZHU
材料科学技术（英）
The volatilization kinetics of antimony trisulfide in steam atmosphere was studied with thermogravimetry at temperatures from 923 to 1123 K. A theoretical model was developed to calculate the overall rate constant and the mass transfer coefficient in gas phases. The experimental results show that the volatilization rate is enhanced with increasing temperature and steam flow rate. The volatilization rate is mainly controlled by the mass transport in gas phases. The apparent activation energy for the process is found to be 59.93 kJ/mol. It is demonstrated that Sb2S3 is dominantly oxidized into Sb2O3 and H2S by water vapor in the volatilization process. Some antimony metal is formed. The reaction mechanism is discussed in accordance with experimental data.
关键词:
Volatilization
,
null
,
null
,
null
王润琴
,
林荣和
,
丁云杰
,
刘佳
,
罗文婷
,
杜虹
,
吕元
催化学报
doi:10.1016/S1872-2067(14)60202-3
通过两种水热处理方式，即800 oC水汽条件和100 oC沸水处理，考察了一锅法制备的FePO4–SBA-15(OP)的水热稳定性.水热处理前后样品的结构变化通过小角X射线衍射和N2物理吸附表征.研究发现，经水热条件下原位生成FePO4修饰后的OP样品具有良好的水热稳定性，并且FePO4的担载量(5%和40%)对OP样品的水热稳定性几乎没有影响.这与文献报道的金属担载量会影响介孔材料水热稳定性的结果不同.此外，还对比研究了浸渍法制备的FePO4/SBA-15(IMP)和商品SBA-15的水热稳定性.结果表明，各样品水热稳定性由强到弱的顺序是OP>IMP>>SBA-15. OP和IMP样品水热稳定性优于纯硅分子筛SBA-15的原因可能是FePO4保护层能抑制介孔材料在水热环境下的结构塌陷. OP样品水热稳定性较IMP样品好的原因可能主要是由于OP样品中存在稳定的Si–O–Fe键和较多的微孔.
关键词:
磷酸铁
,
SBA-15
,
介孔材料
,
水热稳定性
,
水蒸气
,
金属担载量
