高比表面椰壳活性炭和纳米级Pd/C催化剂的制备与表征

Preparation and characterization of cocoanut activated carbons with high specific surface area and Pd/C catalyst

以海南椰壳为原料,粉碎、过筛后,采用二步活化法制备活性炭。先500℃下碳化,然后以KOH为活化剂,炭碱质量比1∶2、1∶3、1∶4,炉温分别为700℃、800℃和900℃在氮气保护下活化。在炭碱比1∶4,活化温度800℃时,得到的活性炭比表面积高达3275m2/g。将得到的比表面积在1100～3200m2/g活性炭通过PdCl2超声浸渍法,水合肼还原制备纳米级钯炭催化剂,经SA、XRD、TEM等分析,得出比表面积越大,纳米钯粒子在活性炭上的分布越均匀,粒子颗粒越小。

The cocoanut activated carbons（AC） with high specific surface area were prepared trorn coconut snell produced in Hainan province after crushed and screened by two-step activatiork First the coconut shell powder was heated to 500℃ ,then mixed with KOH as activator in proportion 1 ： 2,1 ： 3,1 ： 4, respectively. The activation process was done under the protection of nitrogen at 700℃, 800℃ , 900℃ ＇ respectively. When the activation dosage was 4 times of raw materials at 800℃, Specific surface area of activated carbon up to 3275 m2/g. Nanoparticle Pd/C catalysts were prepared by the ultrasound-impregna＂don method, palladium was provided by PdCl2 and reduced by hydrazine hydrate. The catalysts were characterized by surface area and pore size analyzer（SA） , transmission electron microscope（TEM） and Xray diffraction （XRD）. The results showed that nano-palladium particle were homogeneously distributed in activated carbon with the increase of specific surface area ,and the size of particle became smaller.