Chemical Looping Dry Reforming of Methane over Ni-Modified WO3/ZrO2: Cooperative Work of Dispersed Tungstate Species and Ni over the ZrO2 Surface

Proton-exchange membrane water electrolysis (PEMWE) demands highly efficient and stable electrocatalysts for the hydrogen evolution reaction (HER). Noble metals, such as Ir and Pt, are widely employed as HER catalysts as a result of high corrosion resistance and high HER activity under a strong acidic environment. However, as a result of the scarcity and high cost of noble metals, researchers are focusing on developing catalysts with a reduced content of noble metals while enhancing a high catalytic activity per unit mass. Herein, FeCoNiCuIr catalysts were designed using a high-entropy platform to enhance the intrinsic and mass activity. Incorporation of a transition metal (TM) modifies the electronic structure of Ir as a result of charge transfer from the TM to Ir, which optimizes the hydrogen binding energy. FeCoNiCuIr with optimized hydrogen binding energy required a low overpotential of 71 mV at a current density of −10 mA cm −2 . The high mass activity of 3.69 A mg Ir −1 was exhibited in FeCoNiCuIr at the overpotential of 50 mV, which is 92.2% higher than that of the Ir monoelement (1.92 A mg Ir −1). FeCoNiCuIr showed stable performance during chronopotentiometry performed at a constant current density of −100 mA cm −2 for 48 h, demonstrating the excellent durability of the high-entropy alloy (HEA). This study presents the design principle of HEA catalysts capable of improving both activity and durability simultaneously.

“…XAS data were measured in transmission mode, and the Ir foil was used as a reference. The data obtained from XAS were processed using the ATHENA software …”

Section: Methodsmentioning

confidence: 99%

FeCoNiCuIr High-Entropy Alloy Catalysts for Hydrogen Evolution Reactions with Improved Desorption Behavior by Tuning Antibonding Orbital Filling

Choi,

Kwon,

Park

et al. 2023

“…Ni-based OCs are often applied in the CLC due to their high catalytic activity for carbon-based fuel gases such as CH 4 . Studies have shown that the conversion rate of NiO-Fe 2 O 3 /La 0.8 Sr 0.2 FeO 3 to CH 4 in the CLDR reached 97%, and the conversion rate of CO 2 to CO exceeds 90%, which was ascribed to the addition of NiO increasing the crystallinity of Fe 2 O 3 and the formation of NiFe 2 O 4 .…”

Section: Oxygen Carriersmentioning

confidence: 99%

Carbon Dioxide Capture and Hydrogen Production with a Chemical Looping Concept: A Review on Oxygen Carrier and Reactor

Wang,

Chen,

Duan

et al. 2023

The large amount of greenhouse gases produced by the combustion of fossil energy has caused global warming and a series of climate problems. In order to reduce greenhouse gas emissions, captured carbon can be converted into high value-added products, thereby accelerating the transformation of the energy model from fossil fuels to clean energy. Chemical looping technology is considered an efficient and clean potential strategy for converting fuels into syngas and hydrogen. This work describes the chemical looping technology combined with CO 2 or H 2 O reforming to produce CO and H 2 , respectively, and performance analysis such as thermodynamics, kinetics, oxygen transfer capacity, and heat balance were carried out to identify viable oxides. In view of the importance of high-performance, low-cost metal oxides as oxygen carriers (OCs) in this process, this work systematically reviews the classification of such OCs and their applications. In addition, reactors in the 0.2 kW th −1.0 MW th range currently used for chemical looping technology are discussed, which demonstrate their potential to enable the large-scale operation of chemical looping processes. Based on past research progress and additional aspects of chemical looping technology, we firmly believe that this process offers a promising commercial technology that will drive energy transition and carbon neutrality.

“…The catalyst can confine the inner Ni nanoparticle by the external shell, and the small size of Ni nanoparticles can be preserved for fast carbon gasification. The advantages of Ni sintering limitation and carbon deposit reduction positively improve the stability of DRM. − Therefore, as an important type and stable catalyst, it is necessary to review the development of confined Ni catalysts for DRM.…”

Section: Introductionmentioning

confidence: 99%

Review and Outlook of Confined Ni Catalysts for the Dry Reforming of Methane Reaction

Shi,

Tian,

Deng

et al. 2024

Dry reforming of methane (DRM) transforms greenhouse gases of CH 4 and CO 2 to syngas of H 2 and CO, which conduces to reducing emissions of the greenhouse gases and producing sustainable energy chemicals. Catalysts with confined structures can actively and stably catalyze DRM owing to their unique properties of the confinement effect, metal−support interaction, size effect, etc. The properties significantly contribute to resolve the problems of metal sintering and carbon deposition in DRM. This review summarizes the latest developments of confined Ni catalysts for DRM in recent years. The synthetic approaches of the confined catalysts are first introduced, followed by the achievements of DRM over Ni@M 1 O x (M 1 O x = SiO 2 , Al 2 O 3 , and ZrO 2 ), Ni@zeolite (zeolite = SBA-15, MCM-41, and ZSM-5), bimetallic Ni−M 2 @SiO 2 (M 2 = Cu, In, and Co), and multifunctional (Ni/M 3 O x )@SiO 2 (M 3 O x = CeO 2 , ZrO 2 , and Mg phyllosilicate). After illustration of the mono-and bifunctional mechanisms, the remarks and perspectives of DRM are proposed in the end. The review will shed light on fabricating other new confined catalysts for DRM and other reactions.