|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|50111||46780||2016||4 صفحه PDF||سفارش دهید||دانلود کنید|
• Redisperse the Mo oxides by weakening the MoO3-Al2O3 interaction.
• Transform MoO42 − or β-CoMoO4 into polymolybdate species.
• Promote bulk MoO3 to form well-dispersed MoO3 species.
• Remove the CoAl2O4-like species to form more Co-Mo-S active sites.
• The sulfidation and morphology of active species were significantly improved.
Calcined CoMo/γ-Al2O3 catalysts were modified by citric acid (CA) with different CA/Co ratios and the corresponding structure evolutions were systematically characterized. Then combined with HDS activity results, potential redispersion effects of CA were suggested: (i) weaken the MoO3-Al2O3 interaction via competitive interacting with the OH groups of alumina surface to realize the redispersion of Mo oxides; (ii) transform tetrahedral MoO42 − or β-CoMoO4 into octahedral polymolybdate species and promote bulk MoO3 to form well-dispersed MoO3; (iii) remove the CoAl2O4-like species. These effects probably together promote the resulting sulfided catalysts with more type II CoMoS active sites, thus enhancing the HDS activity.
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Journal: Catalysis Communications - Volume 82, 5 July 2016, Pages 20–23