Additional file 1 of Impact of rumination on sleep quality among patients with non‑alcoholic fatty liver disease: a moderated mediation model of anxiety symptoms and resilience

Additional file 1. Demographic and clinical characteristics in relation to anxiety symptoms and PSQI score

Understanding the Product Selectivity of Syngas Conversion on ZnO Surfaces with Complex Reaction Network and Structural Evolution

Recently, a bifunctional oxide–zeolite (OX-ZEO) catalyst was widely studied experimentally, which can selectively convert syngas to light olefins. The performance of OX-ZEO is exceptional, while the mechanism is controversial. In this work, we have first developed an algorithm based on graph theory to establish a complete reaction network for syngas conversion to methanol, ketene, and methane. Combined with density functional theory (DFT) calculations, the activity and selectivity of syngas conversion over zinc oxide (ZnO) are systematically studied by a reaction phase diagram. The key intermediate, ketene, is observed in experiments, which has been first confirmed theoretically in this work. The evolution of ZnO surfaces is found to be a key factor of diverse product selectivity. It is found that methanol production is more favored over the ZnO surfaces with a low oxygen vacancy concentration. As the oxygen vacancy increases, the main product evolves gradually from methanol to ketene and finally to methane. Accordingly, the overall reaction activity increases too. Our prediction from the reaction phase diagram is finally verified by microkinetic modeling

Quantitative Evidence to Challenge the Traditional Model in Heterogeneous Catalysis: Kinetic Modeling for Ethane Dehydrogenation over Fe/SAPO-34

The production of ethylene from ethane dehydrogenation (EDH) is of great importance in the chemical industry, where zeolites are reported to be promising catalysts and kinetic simulations using the energetics from quantum mechanical calculations might provide an effective approach to speed up the development. However, the kinetic simulations with rigorous considerations of the zeolite environment are not yet advanced. In this work, EDH over Fe/SAPO-34 is investigated using quantum mechanical calculations with kinetic simulations. We show that an excellent agreement between the reaction rates from the self-consistent kinetic simulations using the coverage-dependent kinetic model developed in this work and the experimental ones can be achieved. We demonstrate that the adsorbate–adsorbate interactions are of paramount importance to the accuracy of kinetic calculations for zeolite catalysts. Our self-consistent kinetic calculations illustrate that the CH3CH2• radical rather than CH3CH2* is a favored intermediate. Perhaps more importantly, we reveal that the traditional model to describe catalytic reactions in heterogeneous catalysis cannot be used for the kinetics of the system and it may not be appropriate for many real catalytic systems. This work not only builds a framework for accurate kinetic simulations in zeolites, but also emphasizes an important concept beyond the traditional model

Quantitative Studies of the Coverage Effects on Microkinetic Simulations for NO Oxidation on Pt(111)

To advance a reliable microkinetic modeling approach using density functional theory (DFT) energies is of great importance to bridging between experimental results and theoretical calculations, and the current major issue is the coverage effect. In this work, a full microkinetic modeling for NO oxidation using DFT energetics is developed. We show that the calculated turnover frequency (TOF) (0.22 s–1) agrees with the experimental one (∼0.2 s–1) very well, if the coverage effects are properly incorporated. It is found that to include the interactions of adsorbates, namely, (i) O and O, NO and NO (self-interaction), and (ii) O and NO (cross-interaction), is important to obtain accurate kinetic results. Equally important, the interactions between the adsorbates and the transition states of O–O bond breaking and O–NO coupling are also crucial for achieving precise kinetics. We demonstrate that a two-line model can be used to describe accurately both the self and cross adsorbate–adsorbate interactions as well as the coverage effects on the transition states of O2 dissociation and O–NO coupling. The various approximations including Brønsted–Evans–Polanyi (BEP) relations are carefully examined, and the errors involved are quantified. Moreover, a one-line model is tested, which is a simplified approach but gives rise to a good agreement with experimental results

Cu(OTf)₂–Phosphoric Acid-Catalyzed Tandem Oxa-Nazarov Cyclization and Dibromination of Conjugated 1,2-Diketones

A facile tandem oxa-Nazarov cyclization and dibromination has been developed. The combination of Cu­(OTf)2 and diphenyl phosphate (DPP-H) was found to synergistically promote the coupling of conjugated 1,2-diketones and N-bromosuccinimide to form 2,4-dibromo-3­(2H)-furanones in good yields

Computational Insights into Alloying and Confinement Effects on Promoted Activity and Selectivity of C₂ Oxygenate over Rh-Based Catalysts

Improving both activity and selectivity of C2 oxygenate (C2-oxy) over Rh catalysts is challenging. Experimental results have shown that the C2-oxy yield over pure Rh catalysts can be greatly promoted by the combined effects of alloying (Mn promotor) and confinement. Combining density functional theory calculations and microkinetic simulations, we have revealed that the formed Rh–Mn reaction site breaks the scaling relationship between the adsorption energies of intermediates, resulting in a new CO activation path and the stabilization of C2 intermediates, which can improve not only the CO conversion activity but also the C2-oxy selectivity. On the basis of the alloying effect, the confinement effect can further break the scaling relationship between the adsorption energies of intermediates, which can selectively suppress the formation of some useless but abundant species. This leads to the improved effects for the coverage of key intermediates. As a result, the CO conversion activity is further facilitated without the decrease of C2-oxy selectivity. Therefore, the C2-oxy yield can be enhanced. However, without the Mn promotor, the confinement effect alone can only slightly improve the CO conversion activity with poor C2-oxy selectivity. The insights herein regarding the synergistic effects with alloying and confinement are of great significance to regulate the activity and selectivity of C2-oxy in syngas conversion

Computational Design of Spinel Oxides through Coverage-Dependent Screening on the Reaction Phase Diagram

Binary spinel-type metal oxides provide additional opportunities to achieve various catalytic reactions. However, the complexity of the catalytic reaction network, particularly the one containing lattice O involved steps on oxide surfaces, makes it difficult to parse reliable reaction mechanisms. It further challenges the accurate description of catalytic activity in the computational design of catalysts. Therefore, in this work, the rational design of spinel oxides was set out with all elementary steps considered on either perfect or defect sites with also lattice O involved steps. As a result, 2108 possible reaction pathways were enumerated within a complete reaction network for HCl oxidation as a model reaction. The strategy of energy global optimization was performed to obtain favored mechanisms within all possible pathways, building an “energy level” activity trend, namely, the “reaction phase” diagram (RPD). The activity screening for 18 spinel oxides was conducted by descriptors on the RPD. Taking care of the poisoning effect by chloride on the surface, the coverage-dependent screening was performed to search more reliable candidates on the “energy level” trend. Six spinel oxides were finally selected from the coverage-dependent screening on the RPD, where the theoretical activity trend was validated by experiments. At the end, a rigorous rate calculation was performed by the coverage self-consistent microkinetic modeling on the most active surface (CuCo2O4). The reliability of models and approximations used in the scheme of coverage-dependent screening on the RPD, together with the importance of coverage effect, were discussed

Computational Design of Spinel Oxides through Coverage-Dependent Screening on the Reaction Phase Diagram

Binary spinel-type metal oxides provide additional opportunities to achieve various catalytic reactions. However, the complexity of the catalytic reaction network, particularly the one containing lattice O involved steps on oxide surfaces, makes it difficult to parse reliable reaction mechanisms. It further challenges the accurate description of catalytic activity in the computational design of catalysts. Therefore, in this work, the rational design of spinel oxides was set out with all elementary steps considered on either perfect or defect sites with also lattice O involved steps. As a result, 2108 possible reaction pathways were enumerated within a complete reaction network for HCl oxidation as a model reaction. The strategy of energy global optimization was performed to obtain favored mechanisms within all possible pathways, building an “energy level” activity trend, namely, the “reaction phase” diagram (RPD). The activity screening for 18 spinel oxides was conducted by descriptors on the RPD. Taking care of the poisoning effect by chloride on the surface, the coverage-dependent screening was performed to search more reliable candidates on the “energy level” trend. Six spinel oxides were finally selected from the coverage-dependent screening on the RPD, where the theoretical activity trend was validated by experiments. At the end, a rigorous rate calculation was performed by the coverage self-consistent microkinetic modeling on the most active surface (CuCo2O4). The reliability of models and approximations used in the scheme of coverage-dependent screening on the RPD, together with the importance of coverage effect, were discussed

Al³⁺ Dopants Induced Mg²⁺ Vacancies Stabilizing Single-Atom Cu Catalyst for Efficient Free-Radical Hydrophosphinylation of Alkenes

Utilizing heterogeneous catalysts to overcome obstacles for homogeneous reactions is fascinating but very challenging owing to the difficult fabrication of such catalysts based on the character of target reactions. Herein, we report a Al3+ doping strategy to construct single-atom Cu on MgO nanosheets (Cu1/MgO­(Al)) for boosting the free-radical hydrophosphinylation of alkenes. Al3+ dopants in MgO bring about abundant Mg2+ vacancies for stabilizing dense independent Cu atoms (6.3 wt %), while aggregated Cu nanoparticles are formed without Al3+ dopants (Cu/MgO). Cu1/MgO­(Al) exhibits preeminent activity and durability in the hydrophosphinylation of various alkenes with great anti-Markovnikov selectivity (99%). The turnover frequency (TOF) value reaches up to 1272 h–1, exceeding those of Cu/MgO by ∼6-fold and of traditional homogeneous catalysts drastically. Further experimental and theoretical studies disclose that the prominent performance of Cu1/MgO­(Al) derives from the accelerated initiating step of phosphinoyl radical triggered by individual Cu atoms