Ceria nanoparticles as promoters of CO2 electroreduction on Ni YSZ An efficient preparation strategy and insights into the catalytic promotion mechanism

Since many decades nickel yttria stabilized zirconia cermet Ni YSZ has been the most frequently used fuel electrode material for high temperature solid oxide cells SOCs . However, in recent years there has been considerable effort to improve the Ni YSZ performance through surface engineering. In this work, we report a simple strategy to apply nanosized un doped CeOx and Ni doped NiCeOy ceria particles into porous Ni YSZ cermet electrodes via infiltration from hexane solution. Detailed characterization of the particles in their solution revealed differences in the ease of agglomeration, with NiCeOy nanoparticles being better dispersed and thus forming smaller aggregates. This property is critical for the effectiveness of the solution in filling the pores of Ni YSZ cermet and the consequent ceria deposition. In particular, morphological and microstructural characterization reveals that NiCeOy nanoparticles decorate uniformly the pores of Ni YSZ backbone, deep up to the interface with the electrolyte. More importantly, this can be done with relatively high ceria loading per infiltration co firing step. Electrochemical tests demonstrate that infiltrated Ni YSZ fuel electrodes have improved I V performance in CO2 electrolysis as compared to pristine Ni YSZ. Synchrotron based operando NAP XPS experiments using both soft and tender X rays revealed the formation of an ultrathin Ni Ce3 layer on the electrode surface, which can rationalize the ameliorated CO2 electrolysis performanc

Effect of the surface state on the catalytic performance of a Co CeO2 ethanol steam reforming catalyst

This work examines the impact of the Co/CeO₂ catalysts’ surface oxidation state and composition on the ethanol steam reforming (ESR) reaction performance. To this purpose, in situ and ex situ X-ray photoelectron spectroscopy (XPS) combined with on-line mass spectrometry were applied in a wide pressure range (0.2–20 mbar). When the reaction was performed at 0.2 mbar, metallic cobalt and partly reduced cerium oxide were found regardless of the catalysts’ pretreatment conditions. This surface state favors CO and H₂ production, indicating that Csingle bondC bond cleavage is the most important pathway in this pressure regime. A higher reduction degree of ceria gave rise to a larger population of adsorbed hydroxyl groups, which, contrary to the expected behavior, suppressed the activity and the Csingle bondC bond cleavage yield. Under higher pressure (4–20 mbar), gradual oxidation of cobalt and ceria was noted. The presence of ionic cobalt species appears to enhance CO₂ and acetaldehyde yields. On the basis of the present results and the available literature a plausible pressure-dependent reaction mechanism is proposed

A rehabilitation programme for people with multimorbidity versus usual care: A pilot randomized controlled trial

Background: Multimorbidity, the coexistence of two or more chronic conditions, is common in clinical practice. Rehabilitation for people with multimorbidity may provide access to a rehabilitation programme that can address common symptoms and risk factors for multiple chronic diseases. Objective: The aims of this study were to (1) evaluate the feasibility of a rehabilitation programme compared to usual medical care (UMC) in people with multimorbidity and (2) gather preliminary data regarding clinical effects and impact on functional exercise capacity, activities of daily living, health related quality of life and resource utilization. Design: A pilot feasibility parallel randomized controlled trial was undertaken. Adults with multimorbidity were randomized to the rehabilitation programme (intervention) or UMC (control). The duration of the rehabilitation programme was 8 weeks and comprised exercise (1 h, twice weekly) and education (1 h, once weekly). The UMC group did not participate in a structured exercise programme. Results: One hundred people were screened to recruit 16 participants, with a 71% completion rate for the intervention group. The rehabilitation group achieved a mean (standard deviation) improvement in 6-minute walk distance of 44 (41) m and the UMC group of 23 (29) m. Conclusions: This study suggests that it would be feasible to conduct a larger randomized control trial investigating a rehabilitation programme for people with multimorbidity. Low uptake of the study suggests that refinement of the inclusion criteria, recruitment sources and programme model will be needed to achieve the number of participants required

Synthesis of Ni-doped ceria nanoparticles and their unusual surface reduction in hydrogen

This work presents an original approach to preparing pure and Ni-doped CeO2 nanoparticles (NPs) that can be directly drop-casted on a substrate or calcined to form powders. The reduction of the NPs in H-2 is very different than the one usually anticipated for supported Ni-CeO2 catalysts. In situ soft X-ray absorption and infrared spectroscopies revealed that the reduction of Ce4+ into Ce3+ in H-2 proceeds via simultaneous oxidation of Ni2+ ions into Ni delta+(2<3). Comparison with reference samples indicates that Ce4+ ions reduction is promoted over Ni-doped CeO2 NPs, whereas that of Ni2+ is hindered. Theoretical simulation of Ni L-edge spectra suggested that Ni dopant into ceria is in a square planar four-coordinate environment, in contrast to the familiar octahedral symmetry of bulk nickel oxides. Our results reveal that the surface chemistry of Ni-doped CeO2 is quite distinct as compared to that of the individual bulk oxides, which potentially can lead to a different performance of this material, notably in catalytic applications. (C) 2022 Elsevier Ltd. All rights reserved

A rehabilitation programme for people with multimorbidity versus usual care: A pilot randomized controlled trial

Background: Multimorbidity, the coexistence of two or more chronic conditions, is common in clinical practice. Rehabilitation for people with multimorbidity may provide access to a rehabilitation programme that can address common symptoms and risk factors for multiple chronic diseases. Objective: The aims of this study were to (1) evaluate the feasibility of a rehabilitation programme compared to usual medical care (UMC) in people with multimorbidity and (2) gather preliminary data regarding clinical effects and impact on functional exercise capacity, activities of daily living, health related quality of life and resource utilization. Design: A pilot feasibility parallel randomized controlled trial was undertaken. Adults with multimorbidity were randomized to the rehabilitation programme (intervention) or UMC (control). The duration of the rehabilitation programme was 8 weeks and comprised exercise (1 h, twice weekly) and education (1 h, once weekly). The UMC group did not participate in a structured exercise programme. Results: One hundred people were screened to recruit 16 participants, with a 71% completion rate for the intervention group. The rehabilitation group achieved a mean (standard deviation) improvement in 6-minute walk distance of 44 (41) m and the UMC group of 23 (29) m. Conclusions: This study suggests that it would be feasible to conduct a larger randomized control trial investigating a rehabilitation programme for people with multimorbidity. Low uptake of the study suggests that refinement of the inclusion criteria, recruitment sources and programme model will be needed to achieve the number of participants required