Inhibited hydrogen poisoning for enhanced activity of promoters-Ru/Sr2Ta2O7 nanowires for ammonia synthesis

Huang, Jia; Yuan, Mingwei; Li, Xiaozhong; Wang, Yan; Li, Mengwei; Li, Jinjun; You, Zhixiong

doi:10.1016/j.jcat.2020.06.037

Cited by 30 publications

(8 citation statements)

References 58 publications

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“…17,24 For heterogeneous thermal catalysis, hydrogen spillover from metal particles to oxide supports has been widely documented to alleviate the hydrogen poisoning effect for hydrogenation and other reactions. 25,26 Similar hydrogen spillover phenomena have also been experimentally observed and theoretically confirmed for the electrocatalytic HER in acidic electrolytes, for which an expedited HER kinetics is achieved through the migration of hydrogen from H-rich sites to H-deficient sites with superior activity for H 2 formation/release. 27−29 For example, the enhanced acidic HER kinetics by Pt/RuCeO x -PA is attributed to the low energy barrier facilitated by hydrogen spillover from Pt sites to O sites of Pt−O−Ru moieties in Pt/RuCeO x -PA and then to RuO 2 sites for H 2 formation/release.…”

Section: ■ Introductionsupporting

confidence: 55%

“…It has been widely reported that effectively incapacitating the inhibition effect of high-current-density-induced high hydrogen coverage on active sites is critically important to realize the ampere-level current density HER process. , For heterogeneous thermal catalysis, hydrogen spillover from metal particles to oxide supports has been widely documented to alleviate the hydrogen poisoning effect for hydrogenation and other reactions. , Similar hydrogen spillover phenomena have also been experimentally observed and theoretically confirmed for the electrocatalytic HER in acidic electrolytes, for which an expedited HER kinetics is achieved through the migration of hydrogen from H-rich sites to H-deficient sites with superior activity for H 2 formation/release. − For example, the enhanced acidic HER kinetics by Pt/RuCeO x -PA is attributed to the low energy barrier facilitated by hydrogen spillover from Pt sites to O sites of Pt–O–Ru moieties in Pt/RuCeO x -PA and then to RuO 2 sites for H 2 formation/release . The boosted acidic HER kinetics by the EG-Pt/CoP hybridized catalyst is due to the ethylene-glycol ligand concentrated H* around Pt sites that lowers the energy barrier of hydrogen spillover from Pt sites to CoP sites, where H 2 formation/release takes place .…”

Section: Introductionmentioning

confidence: 79%

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Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

et al. 2022

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Water-alkaline electrolysis holds a great promise for industry-scale hydrogen production but is hindered by the lack of enabling hydrogen evolution reaction electrocatalysts to operate at ampere-level current densities under low overpotentials. Here, we report the use of hydrogen spillover-bridged water dissociation/ hydrogen formation processes occurring at the synergistically hybridized Ni 3 S 2 /Cr 2 S 3 sites to incapacitate the inhibition effect of high-current-density-induced high hydrogen coverage at the water dissociation site and concurrently promote Volmer/Tafel processes. The mechanistic insights critically important to enable ampere-level current density operation are depicted from the experimental and theoretical studies. The Volmer process is drastically boosted by the strong H 2 O adsorption at Cr 5c sites of Cr 2 S 3 , the efficient H 2 O* dissociation via a heterolytic cleavage process (Cr 5c -H 2 O* + S 3c (#) → Cr 5c -OH* + S 3c -H # ) on the Cr 5c /S 3c sites in Cr 2 S 3 , and the rapid desorption of OH* from Cr 5c sites of Cr 2 S 3 via a new water-assisted desorption mechanism (Cr 5c -OH* + H 2 O(aq) → Cr 5c -H 2 O* + OH − (aq)), while the efficient Tafel process is achieved through hydrogen spillover to rapidly transfer H # from the synergistically located H-rich site (Cr 2 S 3 ) to the H-deficient site (Ni 3 S 2 ) with excellent hydrogen formation activity. As a result, the hybridized Ni 3 S 2 /Cr 2 S 3 electrocatalyst can readily achieve a current density of 3.5 A cm −2 under an overpotential of 251 ± 3 mV in 1.0 M KOH electrolyte. The concept exemplified in this work provides a useful means to address the shortfalls of amperelevel current-density-tolerant Hydrogen evolution reaction (HER) electrocatalysts.

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Section: ■ Introductionsupporting

confidence: 55%

Section: Introductionmentioning

confidence: 79%

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

et al. 2022

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“…Foo et al 72 studied the yttrium-doped barium zirconate-supported Ru NPs in ammonia synthesis and observed both weak and strong proton trap sites for hydrogen migration. Huang et al 73 used the Sr 2 Ta 2 O 7 structure to spill the excess H adatoms onto the reducible support via an O vacancy mechanism. Another method to alleviate hydrogen poisoning is the construction of new active sites where the ammonia synthesis undergoes a different reaction pathway such as an associative pathway.…”

Section: Design and Synthesis Of Ru-based Catalystsmentioning

confidence: 99%

Challenges and Opportunities of Ru-Based Catalysts toward the Synthesis and Utilization of Ammonia

et al. 2022

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Ammonia is an important chemical for synthesized fertilizers traditionally and for a potential energy vector increasingly. Industrial ammonia synthesis through the Haber–Bosch process is energy-intensive and requires advanced materials to catalyze ammonia synthesis under mild conditions, whereas the utilization of ammonia as a hydrogen carrier via ammonia decomposition is facing a similar situation as well. The developed second-generation Ru-based catalysts performs superior activities over commercial Fe- or Ni-based catalysts; however, it remains challenging to construct effective Ru catalysts to achieve the usage of Ru metal affordably as well as further understanding the nature of Ru catalysis. This Perspective summarizes the recent contributions in engineering Ru-based catalysts via various strategies and related catalysis in ammonia synthesis and decomposition, and it discusses the similarities and differences of Ru catalysis in these reactions. Finally, an overview of this area and opportunities for further investigation are also provided.

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“…The catalysts most commonly used in the Haber–Bosch process are Fe-based; however, these catalysts require a high temperature and pressure to dissociate the NN triple bond (945 kJ mol –1 ), and, therefore, are not suitable for use in conjunction with renewable energy. − In contrast, Ru catalysts show unparalleled ammonia synthesis activity under mild conditions, − but Ru is a rather rare element that is expensive to procure. Co is cheaper and more abundant than Ru, but neat Co is less active than both Ru and Fe because the N 2 molecular adsorption energy of Co is lower than that of Ru and Fe .…”

Section: Introductionmentioning

confidence: 99%

Co Nanoparticle Catalysts Encapsulated by BaO–La₂O₃ Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions

et al. 2022

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Ruthenium catalysts may allow for realization of renewable energy-based ammonia synthesis processes using mild reaction conditions (<400 °C, <10 MPa). However, ruthenium is relatively rare and therefore expensive. Here, we report a Co nanoparticle catalyst loaded on a basic Ba/La 2 O 3 support and prereduced at 700 °C (Co/Ba/La 2 O 3 _700red) that showed higher ammonia synthesis activity at 350 °C and 1.0–3.0 MPa than two benchmark Ru catalysts, Cs + /Ru/MgO and Ru/CeO 2 . The synthesis rate of the catalyst at 350 °C and 1.0 MPa (19.3 mmol h –1 g –1 ) was 8.0 times that of Co/Ba/La 2 O 3 _500red and 6.9 times that of Co/La 2 O 3 _700red. The catalyst showed ammonia synthesis activity at temperatures down to 200 °C. Reduction at the high temperature induced the formation of BaO–La 2 O 3 nanofractions around the Co nanoparticles by decomposition of BaCO 3 , which increased turnover frequency, inhibited the sintering of Co nanoparticles, and suppressed ammonia poisoning. These strategies may also be applicable to other non-noble metal catalysts, such as nickel.

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Inhibited hydrogen poisoning for enhanced activity of promoters-Ru/Sr2Ta2O7 nanowires for ammonia synthesis

Cited by 30 publications

References 58 publications

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

Challenges and Opportunities of Ru-Based Catalysts toward the Synthesis and Utilization of Ammonia

Co Nanoparticle Catalysts Encapsulated by BaO–La₂O₃ Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions

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Inhibited hydrogen poisoning for enhanced activity of promoters-Ru/Sr2Ta2O7 nanowires for ammonia synthesis

Cited by 30 publications

References 58 publications

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential

Challenges and Opportunities of Ru-Based Catalysts toward the Synthesis and Utilization of Ammonia

Co Nanoparticle Catalysts Encapsulated by BaO–La2O3 Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions

Contact Info

Product

Resources

About

Co Nanoparticle Catalysts Encapsulated by BaO–La₂O₃ Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions