金刚石基钯纳米颗粒复合材料的制备及催化性能研究

Preparation and catalytic property of diamond matrix PdNPs composite

以金刚石为基体,经真空放电等离子体烧结(SPS),通过改进的Hummers法合成金刚石@氧化石墨烯(D@GO)中间体,利用NaBH4还原Pd^2+生成钯纳米颗粒静电吸附于中间体后制备了金刚石@氧化石墨烯@钯纳米颗粒(D@GO@PdNPs)复合材料。通过一系列的表征技术对复合材料进行形貌结构、化学成分、分散度和热稳定性分析。结果表明:D@GO复合材料中的介孔结构成功地防止了钯纳米颗粒子的团聚,单晶钯纳米颗粒均匀分散在含有立方金刚石成分的GO片层结构上,当温度达到600℃时复合材料质量仍保持在72.5%。将合成的D@GO@PdNPs复合材料对硝基化合物进行催化实验,发现对4-硝基苯酚(4-NP)和2-硝基苯胺(2-NA)具有较高的催化效果,在连续8个催化循环后,催化4-NP的转化率仍然约95%,并且催化2-NA的转化率仍然约90%。

The diamond@graphene oxide(D@GO)intermediate was synthesized by the improved hummers method using diamond as the matrix through vacuum discharge plasma sintering(SPS).The diamond@oxide graphene@palladium nanoparticles(D@GO@PdNPs)composites were prepared by using NaBH4 to reduce Pd^2+ to form palladium nanoparticles for electrostatic adsorption on intermediates.Through a series of characterization techniques,the morphology,chemical composition,dispersion and thermal stability of the materials were analyzed.The results showed that the mesoporous structure in the(D@GO)composite successfully prevented the reunification of palladium nanoparticles.Single crystal palladium nanoparticles were evenly dispersed in the graphene oxide sheet structure containing cubic diamond components,and the composite mass remained at 72.5% when the temperature reached600℃.The catalytic experiments of the synthetic D@GOS@PdNPs nanocomposites on nitro compounds showed that the catalytic effects of 4-nitrophenol(4-NP)and 2-nitroaniline(2-NA)were high.After eight consecutive catalytic cycles,the conversion rate of catalytic 4-NP was still greater than 95%,and the conversion rate of catalytic 2-NA was still greater than 90%.