CAJ | 학술논문

在丙烷选择氧化制丙烯酸催化剂MoVTeNbOx的活性相M1基础上掺杂一定量的Cr,当Cr/Nb摩尔比为0.002时,催化剂具有很高的丙烯酸选择性(78.3%)和收率(50.7%)；并采用X射线衍射、X射线光电子能谱、程序升温还原、O2程序升温脱附、NH3程序升温脱附和异丙醇氧化等手段对催化剂的构效关系进行了探讨.结果表明,适量Cr的添加可调节催化剂表面Mo6+, V5+和Te4+等物种含量,提高催化剂的氧化能力,使丙烷转化率增加.同时,适量Cr的添加使得催化剂表面酸强度下降,酸性位点数量减少,从而抑制丙烯酸的深度氧化,提高了丙烯酸选择性.
재병완선택양화제병희산최화제MoVTeNbOx적활성상M1기출상참잡일정량적Cr,당Cr/Nb마이비위0.002시,최화제구유흔고적병희산선택성(78.3%)화수솔(50.7%)；병채용X사선연사、X사선광전자능보、정서승온환원、O2정서승온탈부、NH3정서승온탈부화이병순양화등수단대최화제적구효관계진행료탐토.결과표명,괄량Cr적첨가가조절최화제표면Mo6+, V5+화Te4+등물충함량,제고최화제적양화능력,사병완전화솔증가.동시,괄량Cr적첨가사득최화제표면산강도하강,산성위점수량감소,종이억제병희산적심도양화,제고료병희산선택성.
The catalytic performance of active MoVTeNbOx catalysts containing an M1 phase in the partial oxidation of propane to acrylic acid (AA) was greatly improved when an optimal amount of Cr was added. The catalyst containing Cr/Nb (molar ratio=0.002) showed good selectivity (78.3%) and high AA yield (50.7%). The catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, O2 and NH3 temperature-programmed de-sorption, and oxidation of 2-propanol. The relationship between the catalyst structure and catalytic properties was investigated. The results indicated that the amounts of Mo6+, V5+and Te4+species on the catalyst surface were adjusted, and oxidation activity of the catalyst increased, as a result of doping with an appropriate amount Cr, which promoted propane activation. The acid strength be-came weaker, and the number of acid sites on the catalyst surface decreased, which suppressed AA oxidation and improved the selectivity for AA.