氮化硼载体对Ru-Ba/BN氨合成催化剂性能的影响

Effect of Boron Nitride Support on Catalytic Activity of Ru-Ba/BN for Ammonia Synthesis

研究了不同方法合成的氮化硼(BN)的性质及其负载的Ru-Ba催化剂对氨合成的催化性能.采用X射线粉末衍射、N2吸附-脱附、扫描电镜和傅里叶变换红外光谱等手段对所合成的BN样品进行了表征.结果表明,采用程序升温氮化和程序升温还原法均能在低于900℃的条件下合成出较纯的六方相BN,其比表面积分别达到103和138m2/g.其中前者负载Ru-Ba的催化剂活性更高,在475℃,10MPa和10000h–1的条件下出口氨浓度达7.3%,且在550℃热处理30h后,活性基本保持不变.

Boron nitride（BN） nanoparticles with high surface area were prepared by temperature-programmed nitridation and temperature-programmed reduction methods.The catalytic activity of the Ru-Ba/BN ammonia synthesis catalyst was studied.Characterizations by X-ray diffraction,N2 adsorption-desorption,scanning electron microscopy,and Fourier transform infrared spectroscopy were performed to study the crystalline structure,pore structure,and surface properties of the BN material.The characterization results showed that using the above two methods can prepare hexagonal boron nitride with higher surface area,being 103 and 138 m2/g,respectively.The outlet ammonia concentration reached 7.3% under the conditions of 475℃,10 MPa,and 10 000 h–1 for the Ru-Ba/BN catalyst,and the activity was stable after thermal treatment at 550℃ for 30 h.