Alumina and phosphorus-alumina with different morphologies were synthesized by the sol–gel method. The morphology, structure, size, phase composition, acidic properties, and thermal behavior were examined by FESEM, TEM, XRD, FT-IR, BET, EDS, NH₃-TPD, and TGA-DTA, respectively. It can be found that the morphology of alumina can change from worm-like to spherical by using acetonitrile/2-octanol solvent mixture and by modifying the synthesis steps. Also, the semi-crystalline structure of γ-alumina was changed to amorphous with improved surface area (from 150 to 229 m² g⁻¹). The addition of phosphorus pentoxide to amorphous alumina with the ratios of 1:9, 2:8 and 1:1 reduced the surface area of the catalyst after calcination from 229 to 129, 16 and 39 m² g⁻¹, respectively. With the increase of phosphorus/aluminum ratio and an increase in calcination temperature, the structure of phosphorus-alumina transformed from amorphous to crystalline. The reactivity and selectivity of 2-octanol over these composites were monitored using GC and GC-mass analyses.

中文翻译：

---

P 2 O 5对氧化铝的表面改性及其在2-辛醇脱水中的应用

用溶胶-凝胶法合成了不同形态的氧化铝和磷氧化铝。分别通过FESEM，TEM，XRD，FT-IR，BET，EDS，NH ₃ -TPD和TGA-DTA检查形态，结构，尺寸，相组成，酸性和热行为。可以发现，通过使用乙腈/ 2-辛醇溶剂混合物并通过改变合成步骤，氧化铝的形态可以从蠕虫状变为球形。此外，γ-氧化铝的半晶体结构变为具有改善的表面积（从150至229m ²  g ^-1）的非晶态。以1：9、2：8和1：1的比例向无定形氧化铝中添加五氧化二磷将煅烧后催化剂的表面积从229 m减少至129 m，16 m和39 m分别为² g ^-1。随着磷/铝比的增加和煅烧温度的增加，磷-氧化铝的结构从无定形转变为结晶。使用GC和GC质量分析监测2-辛醇在这些复合材料上的反应性和选择性。