Atomic Pd-promoted ZnZrO  solid solution catalyst for CO2 hydrogenation to methanol

Lee, Kyungho; Anjum, Uzma; Araújo, Thaylan Pinheiro; Mondelli, Cecilia; He, Qian; Furukawa, Shinya; Pérez‐Ramírez, Javier; Kozlov, Sergey M.; Yan, Ning

doi:10.1016/j.apcatb.2021.120994

Cited by 89 publications

(85 citation statements)

References 64 publications

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“…In addition, the absence of PdO in the diffractogram of calcined catalysts could be a result of very small crystallite size or the formation of amorphous oxide phases [26]. The XRD analysis of catalyst reduced in H 2 environment revealed distinctive peaks at 41.3 o and 44.5 o , corresponding to the formation of PdZn (111) and PdZn (200) alloyed phases, which agrees with previous reports [26,34,35]. However, no distinct diffraction peak was observed for the Ca phase in any of the samples, which may be due to its very small size, beyond the detection limit of the XRD equipment.…”

Section: X-ray Diffraction (Xrd)supporting

confidence: 89%

“…The authors reported a methanol space-time yield and methanol selectivity of 735 g/kg cat /h and > 90 %, respectively at 260 o C, 50 bar and 30 000 mL/g cat /h GHSV. In another recent article, Pd dispersed on ZnZrO x was reported to exhibit a high concentration of surface oxygen vacancies, which promoted molecular H 2 splitting and stabilized key intermediates for the formation reaction of methanol, thereby affording excellent activity and stability [28].The 0.8 % Pd-ZnZrO 2 catalyst afforded a methanol space-time yield of 100 g/kg cat /h at 240 o C, 50 bar and high GHSV of 24000 mL/g cat /h. These reports indicate that catalytic performance would vary Electronic copy available at: https://ssrn.com/abstract=4159434 based on operating conditions; however, the formation of metal alloy can effectively enhance methanol formation.…”

Section: Introductionmentioning

confidence: 99%

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Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Sharif,

Ojelade,

Alhumaide

et al. 2022

SSRN Journal

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Section: X-ray Diffraction (Xrd)supporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Sharif,

Ojelade,

Alhumaide

et al. 2022

SSRN Journal

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“…52,53 However, many recent studies have found that improving the H 2 activation abilities of the catalysts is helpful to improve the activity of CO 2 hydrogenation to methanol. 54,55,57 Therefore, it is considered that the conventional H 2 −D 2 isotope exchange experiment cannot reflect the activation of H 2 and H* migration on the catalysts during the real CO 2 hydrogenation process where CO 2 is also present in the atmosphere.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…It is generally considered that CO 2 is very stable in thermodynamics and it is difficult to be activated, , but this does not mean that CO 2 activation is the rate-determining step. Some experiments proved that the rate of H 2 activation is much faster than that of methanol generation, so H 2 activation is not a rate-determining step for CO 2 hydrogenation. , However, there were also some recent works focused on improving H 2 activation abilities of catalysts, so as to improve the activities for methanol synthesis. − …”

Section: Introductionmentioning

confidence: 99%

Insights into the Selectivity Determinant and Rate-Determining Step of CO₂ Hydrogenation to Methanol

et al. 2022

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CO 2 hydrogenation to methanol has attracted much attention. The mechanism, the factors affecting selectivity, and the rate-determining step of the reaction have not been clearly concluded. Here, the reaction mechanism on the Cu/ZnO/Al 2 O 3 , the Pd/ZnO, and the ZnZrO x catalysts was studied by in situ infrared spectroscopy and HCOOH temperature-programmed surface reaction (HCOOH-TPSR) experiment. It is shown that the HCOO* mechanism is a feasible mechanism, and the more stable HCOO* on the catalysts is, the higher the selectivity of methanol accompanied with the less CO produced via the decomposition of HCOO*. H 2 −D 2 isotope exchange reaction is inhibited in the presence of CO 2 , which indicates that H 2 activation and H* migration are inhibited by CO 2 adsorbed on the catalysts. As for CO 2 hydrogenation to methanol, the reaction orders of H 2 and CO 2 are close to 0.5 and 0, respectively, indicating that activated H* on the catalysts is insufficient. Comparing CO 2 hydrogenation to methanol reaction and H 2 −D 2 isotope exchange reaction, their H 2 reaction orders are both 0.5 and the two reaction rates show a linear relationship when the temperature changes. It is considered that the rate-determining step of CO 2 hydrogenation to methanol is the migration of H* on the catalysts.

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“…It resulted in a methanol formation rate that was 1.35 times higher than that of the Zn x Zr 1−x O 2−x prepared by a coprecipitation method. 27 In addition, third-component additives (Pd 34 and Ga 35 ) to Zn x Zr 1−x O 2−x were also reported.…”

Section: Introductionmentioning

confidence: 99%

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

et al. 2022

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Recently, Zn x Zr1–x O2–x catalysts have attracted attention as next-generation CO2-to-methanol hydrogenation catalysts. In this study, we examined the effect of the Zn content on CO2-to-methanol hydrogenation over Zn x Zr1–x O2–x catalysts and determined the active-site structure through both calculations and experiments. When the Zn content was low, Zn x Zr1–x O2–x contained Zn clusters (isolated [ZnO a ] clusters and [Zn b O c ] oligomers). The presence of clusters indicates the formation of Zn–O–Zr sites. Interestingly, our calculations revealed that the Zn species in the clusters are easily exposed on the Zn x Zr1–x O2–x surface. This result is in line with the experimental results, suggesting that Zn species were unevenly distributed on the Zn x Zr1–x O2–x surface and deposited near the surface. The addition of excess Zn to ZrO2 led to the formation of both Zn-containing clusters and ZnO nanoparticles. During the reactions, the Zn–O–Zr sites derived from the clusters showed specific activity for CO2-to-methanol hydrogenation. Understanding the active-site structure will lead to the future development of Zn x Zr1–x O2–x catalysts.

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Atomic Pd-promoted ZnZrO solid solution catalyst for CO2 hydrogenation to methanol

Cited by 89 publications

References 64 publications

Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Insights into the Selectivity Determinant and Rate-Determining Step of CO₂ Hydrogenation to Methanol

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

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Atomic Pd-promoted ZnZrO solid solution catalyst for CO2 hydrogenation to methanol

Cited by 89 publications

References 64 publications

Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Elucidating the Promoting Role of Ca on Pdzn/Ceo2catalyst for Co2 Valorization to Methanol

Insights into the Selectivity Determinant and Rate-Determining Step of CO2 Hydrogenation to Methanol

Active Sites on ZnxZr1–xO2–x Solid Solution Catalysts for CO2-to-Methanol Hydrogenation

Contact Info

Product

Resources

About

Insights into the Selectivity Determinant and Rate-Determining Step of CO₂ Hydrogenation to Methanol

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation