CAJ | 학술논문

采用共浸渍法制备了不同 Ni 含量的 Cu/γ-Al2 O3催化剂,在固定床反应器上考察了该催化剂在含硫(SO2,0.01%,体积分数)气氛中对低浓度甲烷(3%)的催化燃烧活性及抗硫中毒稳定性。结果表明,SO2会使 Cu/γ-Al2 O3催化剂发生硫中毒,Ni 的加入可增强其抗硫性能,而且随着 Ni 含量的增加,其抗硫性改善效果越明显。在 Ni 含量为10%的 Cu/γ-Al2 O3催化剂上反应10 h 后,甲烷转化率仍可保持在96%以上。 SEM、XRD 和 TPD 表征结果显示,Ni 的加入促使 Cu/γ-Al2 O3催化剂表面生成 NiAl 2 O 4尖晶石相,提高了催化剂的稳定性。随着 Ni 含量的增加,催化剂表面 Lewis 酸性降低,吸附 SO2的能力减弱,可延缓催化剂硫中毒,同时也缩短了 CO2分子在催化剂表面的停留时间,从而提高了甲烷催化燃烧效率。
채용공침지법제비료불동 Ni 함량적 Cu/γ-Al2 O3최화제,재고정상반응기상고찰료해최화제재함류(SO2,0.01%,체적분수)기분중대저농도갑완(3%)적최화연소활성급항류중독은정성。결과표명,SO2회사 Cu/γ-Al2 O3최화제발생류중독,Ni 적가입가증강기항류성능,이차수착 Ni 함량적증가,기항류성개선효과월명현。재 Ni 함량위10%적 Cu/γ-Al2 O3최화제상반응10 h 후,갑완전화솔잉가보지재96%이상。 SEM、XRD 화 TPD 표정결과현시,Ni 적가입촉사 Cu/γ-Al2 O3최화제표면생성 NiAl 2 O 4첨정석상,제고료최화제적은정성。수착 Ni 함량적증가,최화제표면 Lewis 산성강저,흡부 SO2적능력감약,가연완최화제류중독,동시야축단료 CO2분자재최화제표면적정류시간,종이제고료갑완최화연소효솔。
The Cu / γ-Al2 O3 catalyst promoted with Ni was prepared by incipient wetness impregnation and usedin the catalytic combustion of lean methane (3% ) containing SO2(0. 01% ) in a fixed bed reactor; the effect of Ni addition on the catalytic activity of Cu / γ-Al2 O3 and stability against sulfur poisoning in lean methanecombustion was investigated. The results showed that Cu /γ-Al2 O3 catalyst is facilely poisoned by SO2 in the feed gas and its resistance against sulfur poisoning can be effectively improved through the addition of Ni as a promoter. The stability of Cu / γ-Al2 O3 catalyst is increased with the increase of Ni content; over the Cu / γ-Al2 O3 catalyst promoted by 10% Ni, the conversion of CH4 remains above 96% after reaction at 650 ℃ for 10 h. Thecatalysts were characterized by scanning electron microscopy ( SEM), X-ray diffraction ( XRD) and NH3 temperature-programmed desorption (NH3-TPD); the results illustrated that NiAl2 O4 spinel is formed on the Ni-promoted Cu /γ-Al2 O3 catalyst. Upon the formation of NiAl2 O4 spinel, the surface Lewis acidity is reduced, and meanwhile, the adsorption of SO2 is weakened and the retention time of CO2 on the surface is reduced, all thesemay contribute to the high activity and stability against sulfur poisoning of the Ni-promoted Cu /γ-Al2 O3 catalyst in lean methane combustion.