摘要
运用红外光谱与微量吸附量热联用技术研究了焙烧温度对BaO/γ-Al2O3表面酸碱性的影响。结果表明,γ-Al2O3经1000℃焙烧转化为θ-Al2O3和α-Al2O3,BaOγ-Al2O3经高温焙烧后生成BaO·Al2O3和BaO·6Al2O3等物相。600℃焙烧后,BaO/γ-Al2O3的表面酸性比γ-Al2O3的稍有下降,而碱性却大为增强。经1000℃焙烧后,表面的酸碱性则均大为降低,只有少量较弱的酸碱性位。
Basic metal oxides BaO was added to γ-Al_2O_3 in order to obtain the supports with low acidity and high surface area at high temperatures. The technique combining FT-IR with microcalorimetric adsorption for the adsorption of ammonia and carbon dioxide were used to study the catalysts. XRD results indicated the formation of aluminates on the supported samples calcined at high temperatures, which prevents the transformation of γ-Al_2O_3 to θ-Al_2O_3 and α-Al_2O_3. The addition of BaO did not seem to decrease the surface acidity of γ-Al_2O_3 significantly, but increased the surface basicity substantially when the sample was calcined at 600℃. Calcination of the BaO/γ-Al_2O_3 sample at 1000℃ resulted in the decrease of both acidity and basicity.
出处
《光散射学报》
2003年第4期293-296,共4页
The Journal of Light Scattering
基金
国家科技部973项目(G1999022408)
国家自然科学基金委重点项目(20233040)资助课题
