Effect of the synthesis method on the morphology, textural properties and catalytic performance of La-hexaaluminates in the dry reforming of methane

La-Doped Alumina, Lanthanum Aluminate, Lanthanum Hexaaluminate, and Related Compounds: A Review Covering Synthesis, Structure, and Practical Importance

“…After calcination at 1100 °C for 5 h, surface areas as high as 47.5 m 2 /g (BaAl 12.286 O 19.429 ) and 60 m 2 /g (BaMnAl 11 O 18.5 ) were maintained. However, quite expensive starting materials and adamant reaction conditions (pH, temperature, absence of oxygen and moisture) limit the suitability of most sol–gel processes for large-scale applications. , It should also be kept in mind that the amount of water used in the alkoxide hydrolysis step can have an influence on the morphology and the surface properties of the final product. ,− Jana et al (Table S1, entry 52) developed an advanced sol–gel process for the synthesis of high-purity LHA; cheaper starting materials like boehmite and La-nitrate were used, and seeding of the precursor solution with LHA crystals decreased the formation temperature by ∼100 to ∼1200 °C. An almost single-phase product was observed at 1450 °C, while after calcination at 1600 °C (2 h) a clean LHA phase was formed. , Similarly, Saruhan et al (entry 50) determined by DSC that seeding reduces the crystallization temperature of single-phase LHA by ∼50 to ∼1190 °C.…”

“…In this way, the review article by Choudhary et al demonstrates that the optimization of HA catalysts for the combustion of methane and lower alkanes is mainly driven by changing chemical composition, rather than by structural considerations. Another important aspect of catalyst optimization is the influence of the preparation method/condition on catalyst texture and morphology, which, in turn, has an influence on catalyst activity and selectivity. , …”

“…Another important aspect of catalyst optimization is the influence of the preparation method/condition on catalyst texture and morphology, which, in turn, has an influence on catalyst activity and selectivity. 386,408 The majority of the catalytic applications of HAs deal with combustion 9 , 1 5 2 , 1 5 6 , 1 9 4 , 3 1 4 , 3 1 9 , 3 2 0 , 3 3 7 , 3 4 2 , 3 5 2 , 3 5 5 , 3 5 6 , 364−367,403,407,410,416,420,429,430,495−509 (e.g., of methane for gasturbine applications). 154,306,309,315,338,345,347,359,363,368,369,376,381,415,417,421,510,511 Ni-substituted or -supported HAs are of interest as catalyst precursors for Ni-catalyzed (i) steam reforming (CH 4 + H 2 O → CO + 3H 2 ), 434,512−515 (ii) for partial oxidation of hydrocarbons, in paricular methane (POM, CH 4 + 1 / 2 O 2 → CO + 2H 2 ), 22,32,349,350,398,422,516−521 (iii) for dry reforming of methane (DRM, CH 4 + CO 2 → 2CO + 2H 2 ), 351,395−397,399,400,408,522−525 (iv) for methanation of CO (CO + 3H 2 → CH 4 + H 2 O), 385,404,526 and (v) for the water− gas-shift reaction (CO + H 2 O ⇌ CO 2 + H 2 ).…”

Coke-resistant Ni-based bimetallic catalysts for the dry reforming of methane: effects of indium on the Ni/Al2O3catalyst

“…The fringe spacing of 0.335 nm for the crystal corresponded to deposited carbon. 53 The carbon generated a blocking effect on the metal nanoparticles, thereby preventing the contact of the catalyst with the reactants and accelerating its deactivation. For the spent In/Al 2 O 3 catalyst, the particle interplanar spacings of 0.23 and 0.28 nm corresponded to the (110) and (101) planes of metallic In, and no lattice stripe of carbon species was observed.…”

Structure‐Property Relations of Nickel and Cobalt Substituted Yttrium Aluminum Garnets as Catalyst Materials for Dry Reforming of Methane

“…[2] Nickel and cobalt are promising active metals for the DRM, because of their sufficiently high activity if maintained as metallic nanoparticles, their coke resistivity due to their redox activity in the form of oxides and their comparably low costs [3,4]. Ni and Co catalysts have been examined and applied in various complex oxide structures such as spinels [5] and hexaaluminates [6,7]. The general design features for Ni catalysts in DRM focus on small nanoparti-cle sizes of the active metal/metal oxide that enable a reverse Boudouard reaction pathway for decoking while maintaining catalytic activity [8,9].…”