Bird's-Eye View of the Activity Distribution on a Catalyst Surface via a Machine Learning-Driven Adequate Sampling Algorithm.

Rational design of catalysts relies on a deep understanding of the active centers. The structure and activity distribution of active centers on a surface are two of the central issues in catalysis and important targets of theoretical and experimental investigations. Herein, we report a machine learning-driven adequate sampling (MLAS) framework for obtaining a statistical understanding of the chemical environment near catalyst sites. Combined strategies were implemented to achieve highly efficient sampling, including the decomposition of degrees of freedom, stratified sampling, Gaussian process regression, and well-designed constraint optimization. The MLAS framework was applied to the rate-determining step in NH3 synthesis, namely the N2 activation process. We calculated the produced population function, PA, which provides a comprehensive and intuitive understanding of active centers. The MLAS framework can be broadly applied to other more complicated catalyst materials and reaction networks.

A manganese-based catalyst system for general oxidation of unactivated olefins, alkanes, and alcohols.

Non-noble metal-based catalyst systems consisting of inexpensive manganese salts, picolinic acid and various heterocycles enable epoxidation of the challenging (terminal) unactivated olefins, selective C-H oxidation of unactivated alkanes, and O-H oxidation of secondary alcohols with aqueous hydrogen peroxide. In the presence of the in situ generated optimal manganese catalyst, epoxides are generated with up to 81% yield from alkenes and ketone products with up to 51% yield from unactivated alkanes. This convenient protocol allows the formation of the desired products under ambient conditions (room temperature, 1 bar) by employing only a slight excess of hydrogen peroxide with 2,3-butadione as a sub-stoichiometric additive.

Copyrolysis of Waste Cartons and Polyolefin Plastics under Microwave Heating and Characterization of the Products.

Municipal organic solid waste contains many recoverable resources, including biomass materials and plastics. The high oxygen content and strong acidity of bio-oil limit its application in the energy field, and the oil quality is mainly improved by copyrolysis of biomass with plastics. Therefore, in this paper, a copyrolysis method was utilized to treat solid waste, namely, common waste cartons and waste plastic bottles (polypropylene (PP) and polyethylene (PE)) as raw materials. The products were analyzed by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, GC, and GC/MS to investigate the reaction pattern of the copyrolysis. The results show that the addition of plastics can reduce the residue content by about 3%, and the copyrolysis at 450 °C can increase the liquid yield by 3.78%. Compared with single waste carton pyrolysis, no new product appeared in the copyrolysis liquid products but the oxygen content of the liquid decreased from 65% to less than 8%. The content of CO2 and CO in the copyrolysis gas product is 5-15% higher than the theoretical value; the O content of the solid products increased by about 5%. This indicates that waste plastics can promote the formation of l-glucose and small molecules aldehydes and ketones by providing H radicals and reduce the oxygen content in liquids. Thus, copyrolysis improves the reaction depth and product quality of waste cartons, which provides a certain theoretical reference for the industrial application of solid waste copyrolysis.

Microglial voltage-dependent anion channel 1 signaling modulates sleep deprivation-induced transition to chronic postsurgical pain.

STUDY OBJECTIVES: This study verified that sleep deprivation before and after skin/muscle incision and retraction (SMIR) surgery increased the risk of chronic pain and investigated the underlying roles of microglial voltage-dependent anion channel 1 (VDAC1) signaling. METHODS: Adult mice received 6 hours of total sleep deprivation from 1 day prior to SMIR until the third day after surgery. Mechanical and heat-evoked pain was assessed before and within 21 days after surgery. Microglial activation and changes in VDAC1 expression and oligomerization were measured. Minocycline was injected to observe the effects of inhibiting microglial activation on pain maintenance. The VDAC1 inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and oligomerization inhibitor VBIT-4 were used to determine the roles of VDAC1 signaling on microglial adenosine 5' triphosphate (ATP) release, inflammation (IL-1ß and CCL2), and chronicity of pain. RESULTS: Sleep deprivation significantly increased the pain duration after SMIR surgery, activated microglia, and enhanced VDAC1 signaling in the spinal cord. Minocycline inhibited microglial activation and alleviated sleep deprivation-induced pain maintenance. Lipopolysaccharide (LPS)-induced microglial activation was accompanied by increased VDAC1 expression and oligomerization, and more VDAC1 was observed on the cell membrane surface compared with control. DIDS and VBIT-4 rescued LPS-induced microglial ATP release and IL-1ß and CCL2 expression. DIDS and VBIT-4 reversed sleep loss-induced microglial activation and pain chronicity in mice, similar to the effects of minocycline. No synergistic effects were found for minocycline plus VBIT-4 or DIDS. CONCLUSIONS: Perioperative sleep deprivation activated spinal microglia and increases the risk of chronic postsurgical pain in mice. VDAC1 signaling regulates microglial activation-related ATP release, inflammation, and chronicity of pain.

Initial stage of carbonization of iron during hydrocarbons dissociation: a molecular dynamics study.

The carbonization of iron is a very important early phenomenon in the field of heterogeneous catalysis and the petrochemical industry, but the mechanism is still controversial. In this work, the carbonization mechanism and carbonization structure of iron nanoparticles by different carbon sources (CH4, C2H6, C2H4, C2H2) were systematically investigated using the reactive molecular dynamics method. The results show that saturated alkanes are dehydrogenated while adsorbed, but unsaturated olefins and alkynes undergo bond-breaking while adsorbed. The C-H bond is more likely to break than the C-C bond. Hydrocarbons with high carbon content have a strong ability to carbonize Fe nanoparticles under the same conditions. For C2H4 and C2H2, the C atoms generated from dissociation form a large number of long carbon chains intertwined with branched chains and multiple carbon rings. The C2 species formed by C2H2 after complete dehydrogenation diffuse rapidly to the interior of the nanoparticles, releasing the surface active sites and accelerating the carbonization process. Carbon-rich iron carbides (FeCx) with different Fe/C ratios were obtained by carbonization with different carbon sources. In addition, the Fe(110) surface exhibits the strongest carburizing ability. These findings provide systematic insights into the initial stages of metal Fe carburization.

Research progress on influencing factors of depressive symptoms in adolescents / 中国学校卫生

Abstract@#In recent years, mental health problems such as anxiety and depression among adolescents in China have attracted attention from all walks of life. Given that adolescence is a transitional and critical period for individual development, mental health affect the developmental opportunities. Therefore, in the review, the effects of environment, psychosocial factors and behavioral patterns on depressive symptoms are analyzed by combining with the characteristics of physical and mental development among adolescents. It is found that early adolescence and even childhood should be the key period for the prevention and intervention of depression. In order to formulate effective interventions and prevention strategies, it is proposed that future research should combine real situation in China with active exploration of protective factors and early predictors of depression.

Correlation between physical activity and depressive symptoms in adolescents / 中国学校卫生

Objective@#To analyze the correlation between physical activity and depressive symptoms in adolescents, so as to provide a reference for the early prevention of depression among adolescents.@*Methods@#Using a random cluster sampling method, 8 102 adolescents from Shanghai, Urumqi, Changsha and Kunming were investigated via the Physical Activity Assessment Questionnaire of Chinese Children and Adolescents aged 7 to 18 and the Center for Epidemiologic Studies Depression Scale (CES-D) for physical activity and depressive symptoms. Multivariate Logistic regression analysis was used to analyze the correlation between physical activity and depressive symptoms in adolescents.@*Results@#The proportion of adolescents who met moderate to vigorous physical activity (MVPA) standard was 37.0%, and the detection rate of depressive symptoms was 25.6%. The detection rate of depressive symptomsin compliant with MVPA standard group was significantly lower than that in non compliant group among different age and gender( χ 2=7.62-34.54, P <0.05). Adolescents with severe depressive symptoms had high light intensity physical activity(LPA) duration and low vigorous intensity physical activity(VPA) duration, while adolescents with mild depressive symptoms or asymptomatic adolescents had higher MVPA duration. There were differences in LPA and VPA among adolescents with different levels of depressive symptoms in the overall sample, and the differences were still significant among girls, middle school and statistically significant differences in LPA, moderate intensity physical activity(MPA), MVPA were also found among the high school subgroup. However, differences only in LPA were observed among boys with different levels of depression( H=46.48, 10.31, 25.02, 29.54, 30.25, 19.80, 22.20, 9.54, 8.62, 18.06, P <0.05). Multivariate Logistic regression model showed that gender and duration of MVPA were significantly related to risk of depressive symptoms( OR=1.56, 1.42, P <0.05).@*Conclusion@#Physical activity among adolescents is significantly related to depressive symptoms. MVPA may be an effective measure to reduce the degree of depressive symptoms.To improve the physical health and prevent depression among adolescents, it is important to choose appropriate physical activity types and effectively increase the duration of MVPA.

Mechanically Activated Calcium Channel PIEZO1 Modulates Radiation-Induced Epithelial-Mesenchymal Transition by Forming a Positive Feedback With TGF-ß1.

TGF-ß-centered epithelial-mesenchymal transition (EMT) is a key process involved in radiation-induced pulmonary injury (RIPI) and pulmonary fibrosis. PIEZO1, a mechanosensitive calcium channel, is expressed in myeloid cell and has been found to play an important role in bleomycin-induced pulmonary fibrosis. Whether PIEZO1 is related with radiation-induced EMT remains elusive. Herein, we found that PIEZO1 is functional in rat primary type II epithelial cells and RLE-6TN cells. After irradiation, PIEZO1 expression was increased in rat lung alveolar type II epithelial cells and RLE-6TN cell line, which was accompanied with EMT changes evidenced by increased TGF-ß1, N-cadherin, Vimentin, Fibronectin, and α-SMA expression and decreased E-cadherin expression. Addition of exogenous TGF-ß1 further enhanced these phenomena in vitro. Knockdown of PIEZO1 partly reverses radiation-induced EMT in vitro. Mechanistically, we found that activation of PIEZO1 could upregulate TGF-ß1 expression and promote EMT through Ca2+/HIF-1α signaling. Knockdown of HIF-1α partly reverses enhanced TGF-ß1 expression caused by radiation. Meanwhile, the expression of PIEZO1 was up-regulated after TGF-ß1 co-culture, and the mechanism could be traced to the inhibition of transcription factor C/EBPß expression by TGF-ß1. Irradiation also caused a decrease in C/EBPß expression in RLE-6TN cells. Dual luciferase reporter assay and chromatin immunoprecipitation assay (ChIP) confirmed that C/EBPß represses PIEZO1 expression by binding to the PIEZO1 promoter. Furthermore, overexpression of C/EBPß by using the synonymous mutation to C/EBPß siRNA could reverse siRNA-induced upregulation of PIEZO1. In summary, our research suggests a critical role of PIEZO1 signaling in radiation-induced EMT by forming positive feedback with TGF-ß1.

Simple mechanisms of CH4 reforming with CO2 and H2O on a supported Ni/ZrO2 catalyst.

To understand the metal-support interaction of oxide supported transition metal catalysts, we computed the reaction mechanisms of dry and steam reforming of methane on a tetragonal ZrO2(101) supported Ni catalyst. Based on the limited number of active sites on the surface, an irregular and non-ideal Ni13 cluster on ZrO2(101) is identified as a catalyst. A simple reaction mechanism is proposed, and the first direct dissociation step of CO2, CH4 and H2O is the most difficult based on the computed Gibbs free energies and no surface CHXO and CHXOH intermediates are involved, different from that on the flat Ni(111) surface. Analysis of other supported nickel catalysts shows that not only the support but also the size and shape of the metal clusters play an important role in the reaction mechanisms and kinetics.

PIEZO1 Ion Channel Mediates Ionizing Radiation-Induced Pulmonary Endothelial Cell Ferroptosis via Ca2+/Calpain/VE-Cadherin Signaling.

Pulmonary endothelial cell dysfunction plays an important role in ionizing radiation (IR)-induced lung injury. Whether pulmonary endothelial cell ferroptosis occurs after IR and what are the underlying mechanisms remain elusive. Here, we demonstrate that 15-Gy IR induced ferroptosis characterized by lethal accumulation of reactive oxygen species (ROS), lipid peroxidation, mitochondria shrinkage, and decreased glutathione peroxidase 4 (GPX4) and SLC7A11 expression in pulmonary endothelial cells. The phenomena could be mimicked by Yoda1, a specific activator of mechanosensitive calcium channel PIEZO1. PIEZO1 protein expression was upregulated by IR in vivo and in vitro. The increased PIEZO1 expression after IR was accompanied with increased calcium influx and increased calpain activity. The effects of radiation on lung endothelial cell ferroptosis was partly reversed by inhibition of PIEZO1 activity using the selective inhibitor GsMTx4 or inhibition of downstreaming Ca2+/calpain signaling using PD151746. Both IR and activation of PIEZO1 led to increased degradation of VE-cadherin, while PD151746 blocked these effects. VE-cadherin knockdown by specific siRNA causes ferroptosis-like phenomena with increased ROS and lipid peroxidation in the lung endothelial cells. Overexpression of VE-cadherin partly recused the ferroptosis caused by IR or PIEZO1 activation as supported by decreased ROS production, lipid peroxidation and mitochondria shrinkage compared to IR or PIEZO1 activation alone. In summary, our study reveals a previously unrecognized role of PIEZO1 in modulating ferroptosis, providing a new target for future mitigation of radiation-induced lung injury.

A stable low-temperature H2-production catalyst by crowding Pt on α-MoC.

The water-gas shift (WGS) reaction is an industrially important source of pure hydrogen (H2) at the expense of carbon monoxide and water1,2. This reaction is of interest for fuel-cell applications, but requires WGS catalysts that are durable and highly active at low temperatures3. Here we demonstrate that the structure (Pt1-Ptn)/α-MoC, where isolated platinum atoms (Pt1) and subnanometre platinum clusters (Ptn) are stabilized on α-molybdenum carbide (α-MoC), catalyses the WGS reaction even at 313 kelvin, with a hydrogen-production pathway involving direct carbon monoxide dissociation identified. We find that it is critical to crowd the α-MoC surface with Pt1 and Ptn species, which prevents oxidation of the support that would cause catalyst deactivation, as seen with gold/α-MoC (ref. 4), and gives our system high stability and a high metal-normalized turnover number of 4,300,000 moles of hydrogen per mole of platinum. We anticipate that the strategy demonstrated here will be pivotal for the design of highly active and stable catalysts for effective activation of important molecules such as water and carbon monoxide for energy production.

Atomically Dispersed Ni/α-MoC Catalyst for Hydrogen Production from Methanol/Water.

Methanol-water reforming is a promising solution for H2 production/transportation in stationary and mobile hydrogen applications. Developing inexpensive catalysts with sufficiently high activity, selectivity, and stability remains challenging. In this paper, nickel-supported over face-centered cubic (fcc) phase α-MoC has been discovered to exhibit extraordinary hydrogen production activity in the aqueous-phase methanol reforming reaction. Under optimized condition, the hydrogen production rate of 2% Ni/α-MoC is about 6 times higher than that of conventional noble metal 2% Pt/Al2O3 catalyst. We demonstrate that Ni is atomically dispersed over α-MoC via carbon bridge bonds, forming a Ni1-Cx motif on the carbide surface. Such Ni1-Cx motifs can effectively stabilize the isolated Ni1 sites over the α-MoC substrate, rendering maximized active site density and high structural stability. In addition, the synergy between Ni1-Cx motif and α-MoC produces an active interfacial structure for water dissociation, methanol activation, and successive reforming processes with compatible activity.

PIEZO1 might be involved in cerebral ischemia-reperfusion injury through ferroptosis regulation: a hypothesis.

Stroke is associated with high mortality and extremely high disability rate. Regulating ferroptosis seems to be a promising way to treat ischemic stroke. After stroke, vasogenic edema exerts a mechanical force on surrounding structures, which could activate the mechanosensitive PIEZO1 channel. Our previous research has found that brain cortex PIEZO1 expression was increased in the rat model of middle cerebral artery occlusion (MCAO), and PIEZO1 regulated oxygen-glucose deprivation/reoxygenation (OGD/R) injury in neurons through the calcium signaling. Considering recent studies has identified HIF1α as an essential protein in PIEZO1/calcium signaling, ferroptosis regulation and cerebral ischemia, we herein hypothesize that PIEZO1 might be involved in cerebral ischemia-reperfusion injury through ferroptosis regulation.

Insight into the magnetic moment of iron borides: theoretical consideration from the local coordinative and electronic environment.

Experimentally observed magnetic properties are usually statistically averaged from bulk materials and information associated with the local chemical environment cannot be specified. Against this backdrop, we propose a theoretical strategy to provide an in-depth understanding of the multi-role for metrics that may contribute to the apparent magnetic moment of iron borides. In particular, we demonstrate this strategy through systematic manipulation of the iron/boron stoichiometry of six prototype iron borides to tune their associated local structural and electronic environment to further modulate the resultant magnetic moment. The local coordinative structures of the six iron borides were resolved utilizing bond valence analysis by taking the different coordination shells into account. Furthermore, the local electronic properties of each Fe atom in these iron borides, such as charge transfer, electronic distribution, bonding feature and orbital energy level, were carefully analyzed by Bader analysis, density of states analysis and Crystal Orbital Hamilton Population analysis. From the combination of analyses of both the coordinative and electronic properties of the prototype iron borides, a linear relationship between the local magnetic moment and the bond valence as well as the average energy of the Fe 3d orbitals has been confirmed.

Promoting sleep and circadian health may prevent postoperative delirium: A systematic review and meta-analysis of randomized clinical trials.

This systematic review with meta-analysis and trial sequential analysis of randomized clinical trials aimed to clarify the efficacy of sleep and circadian interventions on preventing postoperative delirium. The search and screening identified 13 trials with great heterogeneity in interventions, surgery types as well as methods for evaluating delirium, sleep and circadian rhythms. Meta-analyses revealed that sleep and circadian interventions were associated with decreased incidences of postoperative delirium (pooled relative risk (RR) = 0.48, 95% confidence interval (CI) = 0.29 to 0.78) compared with control. The pooled incidences of delirium for patients receiving interventions and no intervention (control) were 8.6% and 20.7% respectively. Results of the trial sequential analysis supported the interpretation that sleep and circadian interventions significantly diminished delirium compared to control. Subgroup analysis found that interventions that showed positive efficacy on sleep and circadian outcomes (p < 0.001), but not those without improvements (p = 0.114) or without assessments (p = 0.858), were associated with decreased risk of delirium. Dexmedetomidine sedation (p < 0.001) and timed bright light exposure (p = 0.006) appeared to reduce postoperative delirium. In summary, currently only limited evidence suggests strategies targeted at sleep and circadian health as a useful way to prevent postoperative delirium.

Mechanism of Graphene Formation via Detonation Synthesis: A DFTB Nanoreactor Approach.

With the development of theoretical and computational chemistry, as well as high-performance computing, molecular simulation can now be used not only as a tool to explain the experimental results but also as a means for discovery or prediction. Quantum chemical nanoreactor is such a method which can automatically explore the chemical process based only on the basic mechanics without prior knowledge of the reactions. Here, we present a new method which combines the semiempirical quantum mechanical density functional tight-binding (DFTB) method with the nanoreactor molecular dynamic (NMD) method, and we simulated the reaction process of graphene synthesis via detonation at different oxygen/acetylene mole ratios. The formation of graphene is initiated by the breaking of acetylene (C2H2) molecules by collision into pieces such as H atoms, ethynyl (HC≡C•), and vinylidene (H2C═C:) radicals. It is followed by the formation of long straight carbon chains coupled with a few branched carbon chains, which then turned into  a 2-D framework made of carbon rings. Trace oxygen could modulate the size of the rings during graphene formation and promote the formation of regular graphene with fused six-membered rings as we see, but the addition of high oxygen content makes more C-containing species oxidized to small oxide molecules instead of polymerization. The calculation speed of the DFTB nanoreactor is greatly improved compared to the ab initio nanoreactor, which makes it a valuable option to simulate chemical processes of large sizes and long time scales and to help us uncover the "unknown unknowns".

Piezo1 mediates neuron oxygen-glucose deprivation/reoxygenation injury via Ca2+/calpain signaling.

OBJECTIVE: We investigated whether Piezo1 could regulate oxygen-glucose deprivation/reoxygenation injury of neurons through Ca2+/calpain signaling. METHODS: Piezo1 expression in rat brain cortex and PC12 cells were confirmed by immunohistochemistry, immunofluorescence and Western blotting. The effects of Yoda1 and GsMTx4 on OGD/R-induced decrease in cell viability, increase in cell apoptosis and activation of downstreaming Ca2+/calpain signaling were investigated. Furthermore, calpain signaling was inhibited by PD151746 to see whether Ca2+/calpain signaling participated in the neurotoxic effects of Piezo1 activation. RESULTS: Piezo1 expression was increased in rat cerebral cortex after ischemia/reperfusion and in PC12 cells after OGD/R. Activation of Piezo1 by Yoda1 enhanced OGD/R-induced cell viability inhibition, apoptosis, increase intracellular calcium levels and enhanced calpain activity while GsMTx4 showed the opposite effects. The effects of Piezo1 activation on cell viability and apoptosis were reversed by PD151746. CONCLUSION: Piezo1 could regulate neuron oxygen-glucose deprivation/reoxygenation injury via activation of Ca2+/calpain signaling.

A highly CO-tolerant atomically dispersed Pt catalyst for chemoselective hydrogenation.

The hydrogenation activity of noble metal, especially platinum (Pt), catalysts can be easily inhibited by the presence of a trace amount of carbon monoxide (CO) in the reaction feeds. Developing CO-resistant hydrogenation catalysts with both high activity and selectivity is of great economic interest for industry as it allows the use of cheap crude hydrogen and avoids costly product separation. Here we show that atomically dispersed Pt over α-molybdenum carbide (α-MoC) constitutes a highly CO-resistant catalyst for the chemoselective hydrogenation of nitrobenzene derivatives. The Pt1/α-MoC catalyst shows promising activity in the presence of 5,000 ppm CO, and has a strong chemospecificity towards the hydrogenation of nitro groups. With the assistance of water, high hydrogenation activity can also be achieved using CO and water as a hydrogen source, without sacrificing selectivity and stability. The weakened CO binding over the electron-deficient Pt single atom and a new reaction pathway for nitro group hydrogenation confer high CO resistivity and chemoselectivity on the catalyst.

Prazosin inhibits the growth and mobility of osteosarcoma cells.

BACKGROUND: Osteosarcoma is a primary malignant bone tumor that frequently occurs in adolescents and children, its high aggressiveness and rapid metastasis often resulting in poor prognoses. In previous studies, Prazosin has been shown to possess anti-proliferative properties against prostate cancer and glioblastoma cells. In our study, we investigated Prazosin's underlying mechanisms and its effects on the biological behaviors of osteosarcoma cells. METHODS: Osteosarcoma cell lines MG63 and 143B were treated with different concentrations of Prazosin, and a CCK8 assay assessed its effect on cell viability. Colony formation, Transwell and flow cytometry assays were used to examine its effects on cell proliferation, cell migration, and cell invasion and apoptosis, respectively. The expression of relevant proteins was then examined using western blotting. RESULTS: Our data showed that Prazosin dose-dependently reduced the viability of MG63 and 143B cells and significantly inhibited their clonogenic ability. Moreover, Prazosin attenuated the cell migration and invasion abilities of MG63 and 143B cells when compared with the NC group. It also accelerated cell apoptosis in mitochondrial pathways by regulating Bcl-2/Bax axis and caspase 3. Furthermore, Prazosin treatment inactivated the Akt/mTOR pathway by down-regulating Akt and mTOR phosphorylation (p-Akt, p-mTOR) and the expression of P70 and cyclin D1. CONCLUSIONS: Our data highlights the fact that Prazosin inhibits cell growth, inhibits the motility of osteosarcoma cells, and promotes apoptosis, suggesting that Prazosin is a potential anti-cancer agent in osteosarcoma therapy.

Suppression by Pt of CO adsorption and dissociation and methane formation on Fe5C2(100) surfaces.

To understand the chemical origin of platinum promotion effects on iron based Fischer-Tropsch synthesis catalysts, the effects of Pt on CO adsorption and dissociation as well as surface carbon hydrogenation on the Fe5C2(100) facet with different surface C* contents have been studied using the spin-polarized density functional theory method. CO dissociation initiating from diverse sites was calculated through both direct and H-assisted pathways via the CHO intermediate. On the perfect (100) surface, CO can hardly dissociate, and the surface carbon can be facially hydrogenated to CH4. On the C*-defect and C*-free (100) surfaces, CO can strongly adsorb on the C* vacant sites and direct dissociation is favored to occur. The activity is higher with the decrease of the surface carbon content. When platinum atoms are added on the surfaces, the C*-vacancies have a higher activity for CO dissociation than the new sites generated by Pt adsorption. However, both the CO dissociation and the surface carbon consumption through CH4 formation are hindered. The evolution of surface carbon is predicted to be suppressed by the addition of Pt on the Fe5C2(100) surface.