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US-12617678-B2 - Ceria-supported catalyst

US12617678B2US 12617678 B2US12617678 B2US 12617678B2US-12617678-B2

Abstract

Embodiments include a ceria-supported catalyst. The ceria-supported catalyst may include the formula: Ni/Ce—X-10Cu—O, wherein X is one or more dopants. Embodiments further include a method of processing a feed stock. The method may include contacting the feed stock with a ceria-supported catalyst, sufficient to generate a product including hydrogen and carbon monoxide; wherein the ceria-supported catalyst has the following formula: Ni/Ce—X-10Cu—O , wherein X is one or more dopants. Embodiments further include a method of making a ceria-supported catalyst and other related methods.

Inventors

  • Kyriaki POLYCHRONOPOULOU
  • Angelos M. Efstathiou
  • Aseel Gamal Suliman HUSSIEN
  • Constantinos DAMASKINOS

Assignees

  • Khalifa University of Science and Technology
  • UNIVERSITY OF CYPRUS

Dates

Publication Date
20260505
Application Date
20220831

Claims (9)

  1. 1 . A ceria-supported catalyst, the catalyst comprising the formula: Ni/Ce—X-10Cu—O wherein X is one or more dopants, wherein “10Cu” denotes the catalyst comprises 10 atomic % Cu, wherein the amount of Ce, X, and Cu add to 100 atomic %, and wherein y is a number greater than 0.
  2. 2 . The catalyst of claim 1 , wherein X is one or more dopants selected from La and Sm.
  3. 3 . The catalyst of claim 1 , wherein the catalyst is a cubic fluorite structure.
  4. 4 . The catalyst of claim 1 which catalyzes dry reforming of methane.
  5. 5 . The catalyst of claim 1 further comprising oxygen vacant sites on a surface of the catalyst.
  6. 6 . The catalyst of claim 1 , wherein the catalyst is post-synthetically modified by a ball milling process sufficient to increase oxygen vacant sites by at least about 5% on a surface of the ceria-supported catalyst.
  7. 7 . The catalyst of claim 6 , wherein the ball milling process includes wet ball milling.
  8. 8 . The catalyst of claim 6 , wherein the ball milling process includes dry ball milling.
  9. 9 . The catalyst of claim 1 which catalyzes a reaction selected from one or more of reforming of methane, partial oxidation of methane, and autothermal reforming.

Description

BACKGROUND Dry reforming of methane (DRM) is an endothermic reaction that produces synthesis gas with H2/CO ratio of 1 (CH4+CO2↔2 CO+2 H2; ΔH°(298 K)=+247.3 kJ mol−1). The produced syngas is eventually used to produce high value-added chemicals and fuel. However, this process has not been industrialized yet due to the absence of a robust catalyst that can resist sintering and carbon formation. These phenomena occur due to the high operational temperature of the reaction and the simultaneous side reactions (methane decomposition and CO disproportionation reaction), respectively. Ni-based catalysts are an economically feasible alternative to their noble metal-based counterparts. However, they suffer from carbon formation. Hence, it is vital to tailor a coke-free catalyst by carefully choosing the support's composition and the appropriate synthesis method as it greatly affects the catalyst's performance towards DRM. The active carbon formed via methane decomposition route can be gasified to CO via the oxygen atom from the CO2 reactant or the labile oxygen from the reducible (modified) supports such as ceria, which has the ability to easily switch between oxidation states, releasing a lattice oxygen, and subsequently forming an oxygen vacant site. Oxygen vacant sites promote the CO2 dissociation and the gasification of carbon species on the surface. Studies have shown that doping ceria lattice with trivalent atoms promotes the oxygen mobility and basicity SUMMARY In one or more aspects of the invention, a ceria-supported catalyst is provided. The ceria-supported catalyst may include the formula: Ni/Ce—X-10Cu—O, wherein X is one or more dopants. In one or more further aspects of the invention, a method of processing a feed stock is provided. The method may include contacting the feed stock with a ceria-supported catalyst, sufficient to generate a product including hydrogen and carbon monoxide; wherein the ceria-supported catalyst has the following formula: Ni/Ce—X-10Cu—O, wherein X is one or more dopants. In one or more further aspects of the invention, a method of making a ceria-supported catalyst is provided. The method may include one or more of the following steps: contacting one or more metal precursor with distilled water sufficient to obtain a metal solution; dissolving a complexing agent in distilled water sufficient to make a complexing agent solution; mixing the metal solution and the complexing agent solution and exposing to heat sufficient to form a first solution; separating the first solution and heating an obtained solid in air sufficient to obtain a metal oxide support; impregnating the metal oxide support with a nickel metal precursor; and drying and heating in air; wherein the ceria-supported catalyst has the following formula: Ni/Ce—X-10Cu—O, wherein X is one of La or Sm. BRIEF DESCRIPTION OF DRAWINGS This written disclosure describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to illustrative embodiments that are depicted in the figures, in which: FIG. 1 illustrates a flowchart of a method 100 of making a ceria-supported catalyst, according to some embodiments. FIG. 2 illustrates a flowchart of a method 200 of using a ceria-supported catalyst, according to some embodiments. FIG. 3 illustrates a flowchart of a method 300 of making and post-processing a ceria-supported catalyst using dry ball milling, according to some embodiments. FIG. 4 illustrates a flowchart of a method 400 of making and post-processing a ceria-supported catalyst using wet ball milling, according to some embodiments. FIG. 5 illustrates a schematic illustration of the benefits of ball-milling a catalyst and the preparation method of ceria-supported catalysts, according to some embodiments. FIG. 6 illustrates a schematic illustration of the lattice oxygen 16O are exchanged with 18O for 10 min at 750° C., according to some embodiments. FIG. 7 illustrates the integral rates (mmol g−1Ni s−1) of CH4 conversion after 0.5 h and 12 h of dry reforming of methane (20 vol % CH4/20% CO2/He) at 750° C., and the amount of carbon accumulated after 12 h DRM (Claims 1 & 2), according to some embodiments. FIG. 8 illustrates a dry reforming of methane stability test (100 h) over the 5 wt % Ni/CeLa-10Cu—O catalyst. T=750° C., 40% CH4/40% CO2/20% He, GHSV˜30,000 h−1, according to some embodiments. FIG. 9 illustrates CO2- and CO-TPO traces recorded over the 5 wt % Ni/Ce—La-10Cu—O catalyst after 100 h of DRM (40% CH4/40% CO2/20% He) at 750° C. and GHSV˜30,000 h−1, according to some embodiments. FIG. 10A illustrates a HRTEM image of the fresh 5 wt % Ni/Ce—La-10Cu—O catalyst, according to some embodiments. FIG. 10B illustrates a Red-Green-Blue (RGB) mapping analysis of the fresh 5 wt % Ni/Ce—La-10Cu—O catalyst. Red (R): Cu, Green (G): Ni, Blue (B): O, according to some embodiments. FIG. 10C illustrates a RGB analysis of the Ce—La-10Cu—O support alone. Red (R): Ce, Green (G): La, Blue (B): Cu, according to som