In situ DRIFTS investigation of the steam reforming of methanol over Pt/ceria

Methanol adsorption over both supported NiSn Nps and analogous NiSn catalyst prepared by impregnation was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to gain insights into the basis of hydrogen production from methanol steam reforming. Different intermediate species such as methoxides with different geometry (bridge and monodentate) and formate species were identified after methanol adsorption and thermal desorption. It is proposed that these species are the most involved in the methanol steam reforming reaction and the major presence of metal-support interface sites in supported NiSn Nps leads to higher production of hydrogen. On the basis of these results, a plausible reaction mechanism was elucidated through the correlation between the thermal stability of these species and the evolution of the effluent gas released. In addition, it was demonstrated that DME is a secondary product generated by condensation of methoxides over the acid sites of alumina support in an acid-catalyzed reaction.

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In situ investigations of structure–activity relationships of a Cu/ZrO2 catalyst for the steam reforming of methanol

Journal of Catalysis ◽

10.1016/j.jcat.2005.04.024 ◽

2005 ◽

Vol 233 (2) ◽

pp. 297-307 ◽

Cited By ~ 76

Author(s):

A SZIZYBALSKI ◽

F GIRGSDIES ◽

A RABIS ◽

Y WANG ◽

M NIEDERBERGER ◽

...

Keyword(s):

Steam Reforming ◽

Steam Reforming Of Methanol ◽

Structure Activity Relationships ◽

Structure Activity ◽

Zro2 Catalyst

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Insight into the Promoting Role of Er Modification on SO2 Resistance for NH3-SCR at Low Temperature over FeMn/TiO2 Catalysts

Catalysts ◽

10.3390/catal11050618 ◽

2021 ◽

Vol 11 (5) ◽

pp. 618

Author(s):

Huan Du ◽

Zhitao Han ◽

Xitian Wu ◽

Chenglong Li ◽

Yu Gao ◽

...

Keyword(s):

Low Temperature ◽

Catalyst Surface ◽

Impregnation Method ◽

In Situ Drifts ◽

Tio2 Catalyst ◽

Nh3 Scr ◽

Nh3 Adsorption ◽

So2 Resistance ◽

Fast Scr

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.

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Glycerol Hydrogenolysis with In Situ Hydrogen Produced via Methanol Steam Reforming: The Promoting Effect of Pd on a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽

10.3390/catal11010110 ◽

2021 ◽

Vol 11 (1) ◽

pp. 110

Author(s):

Yuanqing Liu ◽

Chau T. Q. Mai ◽

Flora T. T. Ng

Keyword(s):

Steam Reforming ◽

Catalyst Activity ◽

Promoting Effect ◽

Glycerol Conversion ◽

Glycerol Hydrogenolysis ◽

Glycerol Dehydration ◽

Effect Of Pd ◽

Al2o3 Catalyst ◽

Reaction Equilibrium

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.

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