Subnanometric Osmium Clusters Confined on Palladium Metallenes for Enhanced Hydrogen Evolution and Oxygen Reduction Catalysis.

Highly efficient, cost-effective, and durable electrocatalysts, capable of accelerating sluggish reaction kinetics and attaining high performance, are essential for developing sustainable energy technologies but remain a great challenge. Here, we leverage a facile heterostructure design strategy to construct atomically thin Os@Pd metallenes, with atomic-scale Os nanoclusters of varying geometries confined on the surface layer of the Pd lattice, which exhibit excellent bifunctional properties for catalyzing both hydrogen evolution (HER) and oxygen reduction reactions (ORR). Importantly, Os5%@Pd metallenes manifest a low η10 overpotential of only 11 mV in 1.0 M KOH electrolyte (HER) as well as a highly positive E1/2 potential of 0.92 V in 0.1 M KOH (ORR), along with superior mass activities and electrochemical durability. Theoretical investigations reveal that the strong electron redistribution between Os and Pd elements renders a precise fine-tuning of respective d-band centers, thereby guiding adsorption of hydrogen and oxygen intermediates with an appropriate binding energy for the optimal HER and ORR.

Dynamic Behavior of Intermediate Adsorbates to Control Activity and Product Selectivity in Heterogeneous Catalysis: Methanol Decomposition on Pt/TiO2(110).

Dynamic behavior of intermediate adsorbates, such as diffusion, spillover, and reverse spillover, has a strong influence on the catalytic performance in oxide-supported metal catalysts. However, it is challenging to elucidate how the intermediate adsorbates move on the catalyst surface and find active sites to give the corresponding products. In this study, the effect of the dynamic behavior of methoxy intermediate on methanol decomposition on a Pt/TiO2(110) surface has been clarified by combination of scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and density functional theory (DFT) calculations. The methoxy intermediates were formed by the dissociative adsorption of methanol molecules on Pt nanoparticles at room temperature followed by spillover to the TiO2(110) support surface. TPD results showed that the methoxy intermediates were thermally decomposed at >350 K on the Pt sites to produce CO (dehydrogenation) and CH4 (C-O bond scission). A decrease of the Pt nanoparticle density lowered the activity for the decomposition reaction and increased the selectivity toward CH4, which indicates that the reaction is controlled by diffusion and reverse spillover of the methoxy intermediates. Time-lapse STM imaging and DFT calculations revealed that the methoxy intermediates migrate on the five-fold coordinated Ti (Ti5c) sites along the [001] or [11¯0] direction with the aid of hydrogen adatoms bonded to the bridging oxygens (Obr) and can move over the entire surface to seek and find active Pt sites. This work offers an in-depth understanding of the important role of intermediate adsorbate migration in the control of the catalytic performance in oxide-supported metal catalysts.

Stacking of a Cofacially Stacked Iron Phthalocyanine Dimer on Graphite Achieved High Catalytic CH4 Oxidation Activity Comparable to That of pMMO.

Numerous biomimetic molecular catalysts inspired by methane monooxygenases (MMOs) that utilize iron or copper-oxo species as key intermediates have been developed. However, the catalytic methane oxidation activities of biomimetic molecule-based catalysts are still much lower than those of MMOs. Herein, we report that the close stacking of a µ-nitrido-bridged iron phthalocyanine dimer onto a graphite surface is effective in achieving high catalytic methane oxidation activity. The activity is almost 50 times higher than that of other potent molecule-based methane oxidation catalysts and comparable to those of certain MMOs, in an aqueous solution containing H2O2. It was demonstrated that the graphite-supported µ-nitrido-bridged iron phthalocyanine dimer oxidized methane, even at room temperature. Electrochemical investigation and density functional theory calculations suggested that the stacking of the catalyst onto graphite induced partial charge transfer from the reactive oxo species of the µ-nitrido-bridged iron phthalocyanine dimer and significantly lowered the singly occupied molecular orbital level, thereby facilitating electron transfer from methane to the catalyst in the proton-coupled electron-transfer process. The cofacially stacked structure is advantageous for stable adhesion of the catalyst molecule on the graphite surface in the oxidative reaction condition and for preventing decreases in the oxo-basicity and generation rate of the terminal iron-oxo species. We also demonstrated that the graphite-supported catalyst exhibited appreciably enhanced activity under photoirradiation owing to the photothermal effect.

Pd-PdO Nanodomains on Amorphous Ru Metallene Oxide for High-Performance Multifunctional Electrocatalysis.

Developing highly efficient multifunctional electrocatalysts is crucial for future sustainable energy  pursuits, but remains a great challenge. Herein, a facile synthetic strategy is used to confine atomically thin Pd-PdO nanodomains to amorphous Ru metallene oxide (RuO2 ). The as-synthesized electrocatalyst (Pd2 RuOx-0.5 h) exhibits excellent catalytic activity toward the pH-universal hydrogen evolution reaction (η10  = 14 mV in 1 m KOH, η10  = 12 mV in 0.5 m H2 SO4 , and η10  = 22 mV in 1 m PBS), alkaline oxygen evolution reaction (η10  = 225 mV), and overall water splitting (E10  = 1.49 V) with high mass activity and operational stability. Further reduction endows the material (Pd2 RuOx-2 h) with a promising alkaline oxygen reduction activity, evidenced by high halfway potential, four-electron selectivity, and excellent poison tolerance. The enhanced catalytic activity is attributed to the rational integration of favorable nanostructures, including 1) the atomically thin nanosheet morphology, 2) the coexisting amorphous and defective crystalline phases, and 3) the multi-component heterostructural features. These structural factors effectively regulate the material's electronic configuration and the adsorption of intermediates at the active sites for favorable reaction energetics.

A new interpretation of the √7×√7 R19.1° structure for P adsorbed on a Ni(111) surface.

We have studied P adsorption on Ni(111), a system which shows complex adsorbate structures. We determined the phase diagram of the surface P adsorbed on Ni(111). At low coverage, amorphous P was observed. At temperatures between 373 and 673 K and coverages above 0.1 monolayer, we found a 7 × 7   R 19.1 ∘ structure, but above 673 K, other complex structures were created. These structures seemed to correlate with each other and we reinterpret a 7 × 7   R 19.1 ∘ structure of P adsorbed on Ni(111) based on the similarities of these surface structures. The new rectangular structure for the 7 × 7   19.1 ∘ is discussed in relation to the Ni2P local structure.

Long-term safety and efficacy of weekly subcutaneous tocilizumab monotherapy in patients with rheumatoid arthritis who had an inadequate response to subcutaneous tocilizumab every other week: Results from the open-label extension of the SHINOBI study.

Objective: To evaluate the long-term safety and efficacy of subcutaneous tocilizumab (TCZ-SC) monotherapy administered weekly (qw) in patients with rheumatoid arthritis who had an inadequate response to TCZ-SC every other week (q2w). Methods: Patients who completed 12 weeks of double-blind treatment with either TCZ-SC q2w monotherapy or TCZ-SC qw monotherapy were switched to or continued to receive open-label treatment with TCZ-SC qw monotherapy for 40 weeks. Safety and efficacy were assessed. Subgroup analyses of Disease Activity Score based on 28 joints using erythrocyte sedimentation rate (DAS28-ESR) were performed at 12 weeks. Results: The incidence of adverse events was 464.4/100 patient-years (PY). The incidence of infection was 121.3/100 PY. The safety profile of TCZ-SC qw monotherapy was consistent with that of prior studies of TCZ. No additional safety concerns were observed. Improvement from baseline in DAS28-ESR was maintained at week 52 in patients who continued TCZ-SC qw and improved in patients who switched from TCZ-SC q2w to qw. At week 12, the efficacy of TCZ-SC qw monotherapy was greater than that of TCZ-SC q2w monotherapy irrespective of weight and BMI subgroups. Conclusion: The long-term weekly dosing of TCZ-SC monotherapy was well tolerated and efficacy was maintained over 52 weeks.

A randomized, double-blind, parallel-group, phase III study of shortening the dosing interval of subcutaneous tocilizumab monotherapy in patients with rheumatoid arthritis and an inadequate response to subcutaneous tocilizumab every other week: Results of the 12-week double-blind period.

OBJECTIVE: To determine the efficacy and safety of subcutaneous tocilizumab (TCZ-SC) monotherapy every week (qw) versus every other week (q2w) in patients with rheumatoid arthritis who had an inadequate response to TCZ-SC q2w. METHODS: Adult patients in Japan with inadequate response to TCZ-SC q2w were randomized to either TCZ-SC 162 mg qw monotherapy or TCZ-SC 162 mg q2w monotherapy for 12 weeks (double-blind). The primary endpoint was the change from baseline in adjusted Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR) at week 12. Efficacy, safety and pharmacokinetics were assessed. RESULTS: TCZ-SC qw was superior to TCZ-SC q2w for adjusted mean change in DAS28-ESR from baseline to week 12. The difference in the change in DAS28-ESR between TCZ-SC qw and q2w was -1.21 (95%CI: -2.13, -0.30, p = .0108). A higher proportion of patients receiving TCZ-SC qw achieved DAS28-ESR remission/low disease activity than TCZ-SC q2w. Adverse events were 71.4% and 66.7% for TCZ-SC qw and q2w, respectively; infection was the most common event with one fatal case with TCZ-SC qw. CONCLUSIONS: In patients with inadequate response to TCZ-SC q2w, shortening the dosing interval to qw improved efficacy with acceptable tolerability. Occurrence of infection for both TCZ q2w and qw is important and needs careful attention.