CAJ | 학술논문

采用高分子辅助的浸渍还原法,制备得到膨胀石墨( EG)负载的纳米钯催化剂( Pd-EG),采用X射线衍射( XRD)、透射电子显微镜( TEM)、X射线光电子能谱( XPS)等手段对催化剂组成、结构、形貌和价态进行了表征,并考察了Pd-EG催化剂在六价铬还原反应中的活性.结果表明,催化剂中纳米钯颗粒均匀分散在膨胀石墨上,平均粒径为4.37 nm,金属负载量质量分数为0.446%.该催化剂对六价铬还原反应具有良好的催化性能,可将六价铬完全转化为三价铬,在pH=4.0及45℃条件下反应转化频率( TOF)达到3186 h-1；催化剂经过多次重复使用后的活性仍保持稳定.
채용고분자보조적침지환원법,제비득도팽창석묵( EG)부재적납미파최화제( Pd-EG),채용X사선연사( XRD)、투사전자현미경( TEM)、X사선광전자능보( XPS)등수단대최화제조성、결구、형모화개태진행료표정,병고찰료Pd-EG최화제재륙개락환원반응중적활성.결과표명,최화제중납미파과립균균분산재팽창석묵상,평균립경위4.37 nm,금속부재량질량분수위0.446%.해최화제대륙개락환원반응구유량호적최화성능,가장륙개락완전전화위삼개락,재pH=4.0급45℃조건하반응전화빈솔( TOF)체도3186 h-1；최화제경과다차중복사용후적활성잉보지은정.
Expanded graphite( EG) supported palladium nanocatalysts( Pd-EG) were synthesized by wet-im-pregnation reduction method with the aid of a polymer stabilizer. The catalysts were characterized by various techniques including X-ray diffraction( XRD) , transmission electron microscope( TEM) and X-ray photoelec-tron spectroscopy( XPS) . The catalytic activities of the synthesized Pd-EG nanocatalysts were evaluated for the reduction of Cr(Ⅵ) . The results indicated that the Pd loading of Pd-EG nanocatalysts was 0. 446%( mass fraction) in the form of Pd nanoparticles with an average diameter of 4. 37 nm. The Pd-EG nanocatalysts show high catalytic activity in the complete reduction of Cr (Ⅵ) to Cr (Ⅲ) with a turn-over frequency ( TOF ) of 3186 h-1 at pH=4 . 0 and 45 ℃. The Pd-EG catalysts exhibit efficient and stable catalytic performance even after several times of recycles.