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Preferential CO Oxidation in H 2 -rich streams is a promising approach to decrease CO concentrations below 10 ppm for fuel cell applications. Herein, Cu catalysts supported on commercial CeO 2 are prepared by a simple ball-milling method with different Cu loadings (0.25, 0.5, and 1 wt%). The catalysts are characterized by various methods, including XRD, BET, STEM-EELS, and H 2 -TPR. The results show that the catalysts are highly active and selective during CO-PROX in 80 vol% H 2 -streams at different temperatures. Moreover, all catalysts exhibited high stability and 100 % CO 2 -selectivity throughout 75 h of reaction at 90 °C. However, increasing Cu loading caused a decrease in Cu-mass-normalized rate due to the formation of less active CuO x clusters. The combined results from operando DRIFTS, EPR and NAP-XPS reveal that single Cu atom sites on CeO 2 are the key factor for the enhanced catalytic performance while the decreased activity is due to CuO x cluster formation. • Supported Cu-single sites on commercial CeO 2 - are highly active and selective for CO-PRX reaction. • Cu/CeO 2 catalysts prepared by simple ball-milling method. • No appreciable deactivation during 75 h on stream with 100 % selectivity at 90 °C. • CuO x cluster/nanoparticles are less active for CO-PROX. • Cu2+−O–Ce4+ and Cu+−□−Ce3+ moieties are the active sites for CO-PROX. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gd, La and Sc improve stability of low Ni content Al 2 O 3 -MgO catalysts in DRM. • Rare earth elements stabilize Ni dispersion and promote CO 2 activation. • Gd sufficiently establishes both effects. • Outstanding stability in excess methane (CH 4 /CO 2 = 2) at 630 and 750 °C. • Successful exceptional long-term tests over 100 h at high space velocity. Biogas consists of a larger part of methane and a smaller part of carbon dioxide. Reforming biogas is highly desirable due to the direct conversion of the two components, yet not possible due to the current state of catalyst development. For such dry reforming of methane-rich gases (CH 4 /CO 2 = 2) we now present catalysts with low Ni loading (2.5 wt%) modified with Gd, Sc, or La. The best catalyst reaches 49% CH 4 conversion and 95% CO 2 conversion at 750 °C. The La-modification only shows limited influence on coking and protection against catalyst deactivation although this catalyst exposed highest basicity. On the other side, Sc- and especially Gd-modified catalysts exposed stronger metal-support interaction and thus enhanced stabilization of fine Ni particles during the reaction, which is critical to preserve high performance in CH 4 -rich DRM. This suppressed carbon deposition and the growth of structured carbon as evidenced by STEM images and TPO of spent catalysts. In this way, exceptionally high specific H 2 productivity (94 l/(g cat ·h)) compared to literature was obtained on Gd-modified catalyst, and, most noteworthy, after extending the time on stream from 8 to 100 h the amount of deposited coke increased only from 3 to 4 wt%. [ABSTRACT FROM AUTHOR]

• Rh supported large pore Zr-MOFs with different pore structure were prepared and characterized. • The catalysts show markedly different catalytic effects in the hydroformylation reaction with different framework types. • All catalysts show superior activity at low rh content as expected from rh single site catalysts. • A markedly impact of the pore structure on selectivity to aldehydes and enones is observed. • Catalytic differences are due to different accessibility of rh located in various framework sites. Three large pore crystalline zirconium-based metal-organic frameworks (Zr-MOFs) of different pore sizes (6–18 Å) and structure were synthesized and used for the preparation of the Rh-supported catalysts Rh@UiO-66, Rh@UiO-67, and Rh@MOF-808. The materials were characterized by XRD, FTIR, SEM/TEM, XPS, and nitrogen adsorption/desorption measurements. The catalytic performance was studied in the hydroformylation of olefins to the corresponding aldehydes. A series of n-alk-1-enes of different chain length was used to study the influence of the pore size and structure. The results show that the Zr-MOF-based catalysts are very active and show high aldehyde selectivity. The superior catalytic properties are assigned to the presence of highly dispersed active Rh sites located at the isolated zirconia moieties and the enhanced accessibility of sites via the large pores. Nevertheless, marked differences in the catalytic performance of the catalysts are observed, which are assigned to the different accessibility of Rh located at various secondary building units. [Display omitted] [ABSTRACT FROM AUTHOR]

• ZrO 2 -based catalysts with Rh, Ru, Ir or Pt were tested for C 3 H 8 dehydrogenation. • The metals on LaZrO x and YZrO x positively affect the rate: Rh > Ru > Ir > Pt. • The metals facilitate formation of Zr cus sites and accelerate H 2 formation. • The metals affect propene adsorption and thus undesired side reactions. • C 3 H 6 selectivity over Rh- or Ru-containing catalysts increases with temperature. A series of catalysts on the basis of ZrO 2 , LaZrO x and YZrO x with supported Rh, Ru, Pt or Ir nanoparticles (NPs) were prepared. They were tested in the non-oxidative dehydrogenation of propane (PDH) to elucidate the effects of (i) the kind of supported metal and its loading, (ii) the size (1 nm or 5 nm) of NPs, (iii) metal oxide promoter for ZrO 2 and (iv) reaction temperature on PDH performance. Although the metals did not directly participate in propene formation, they improve catalyst activity through (i) promotion of Zr cus (cus means coordinatively unsaturated) formation and (ii) acceleration of hydrogen formation. The kind of metal was also established to be decisive for propene adsorption. The latter property has a negative effect on catalyst activity and propene selectivity. The most active Rh/YZrO x catalyst with 0.05 wt% Rh revealed about 1.6 times higher propene formation rate than a commercial-like K-CrO x /Al 2 O 3 or the state-of-the-art Ru/YZrO x. [ABSTRACT FROM AUTHOR]