CAJ | 학술논문

PdHx相是Pd/C催化剂中一种重要的活性物种。研究以浸渍-水合肼还原法制备出PdHx含量较高的Pd/C催化剂，通过XRD、XPS和TEM等表征方法研究了还原方式和条件及载体活性炭的预处理条件对催化剂中PdHx含量的影响，以无氢条件下的2,6-二甲基苯酚胺化法合成2,6-二甲基苯胺作为探针反应，验证了PdHx含量与催化活性的相关性。结果表明：以2.5%(wt)硝酸预处理的活性炭为载体，水合肼为还原剂，在40℃还原制得的催化剂具有较高的PdHx含量，以其为催化剂时原料的转化率和产品的选择性分别高达59.8%和87.3%。说明PdHx是该反应的活性相，其含量与载体预处理时的硝酸浓度密切相关。
PdHx상시Pd/C최화제중일충중요적활성물충。연구이침지-수합정환원법제비출PdHx함량교고적Pd/C최화제，통과XRD、XPS화TEM등표정방법연구료환원방식화조건급재체활성탄적예처리조건대최화제중PdHx함량적영향，이무경조건하적2,6-이갑기분분알화법합성2,6-이갑기분알작위탐침반응，험증료PdHx함량여최화활성적상관성。결과표명：이2.5%(wt)초산예처리적활성탄위재체，수합정위환원제，재40℃환원제득적최화제구유교고적PdHx함량，이기위최화제시원료적전화솔화산품적선택성분별고체59.8%화87.3%。설명PdHx시해반응적활성상，기함량여재체예처리시적초산농도밀절상관。
PdHx phase is an important reactive species in the Pd/C catalyst. The Pd/C catalyst with high content of PdHx phase was controllably prepared by the impregnation-hydrazine hydrate reduction method, and the influences of reduction methods, reduction conditions and the pretreatment conditions of the activated carbon on the PdHx content were investigated by XRD, XPS and TEM. By using the amination of 2,6-dimethyl phenol in the absence of hydrogen as a probe reaction, the relationship between PdHx content and catalytic activity was also studied. The results show that the Pd/C catalyst with high amount of PdHx can be obtained by using activated carbon support pretreated with 2.5%(wt) HNO3 and reducing the catalyst with hydrazine hydrate as reductor at 40℃. And over this catalyst the conversion of 2,6-dimethylphenol and the selectivity for 2,6-dimethylaniline are as high as 59.8%and 87.3%, respectively. It shows that the PdHx is the reactive phase of amiation reaction and its content is closely related to the concentration of HNO3 in the pretreatment process.