CO Coverage Research Articles

DFT study on bimetallic Pt/Cu(1 1 1) as efficient catalyst for H2 dissociation

To design a catalyst for the dissociation of H2 with better CO-tolerance performance is very important for proton exchange membrane fuel cells (PEMFCs) towards high efficiency. With slab model, the catalytic properties of overlayer Pt on Cu substrate (Pt/Cu) are analyzed by first-principle calculations. The CO saturation coverage (40%) on Pt2/Cu is found to be lower than that of pure Pt (about 75%). The dissociation barrier from H2 to H is less than 0.4 eV under the saturation coverage of CO. On the basis of kinetics of proton formation, the CO-tolerance ability on double-layer Pt with Cu is found to be greatly improved compared with that on pure Pt. It is expected that Pt overlayer on Cu(1 1 1) is a potential anode material with lower cost for PEMFCs.

Carbon Monoxide Poisoning Resistance and Structural Stability of Single Atom Alloys

Platinum group metals (PGMs) serve as highly active catalysts in a variety of heterogeneous chemical processes. Unfortunately, their high activity is accompanied by a high affinity for CO and thus, PGMs are susceptible to poisoning. Alloying PGMs with metals exhibiting lower affinity to CO could be an effective strategy toward preventing such poisoning. In this work, we use density functional theory to demonstrate this strategy, focusing on highly dilute alloys of PGMs (Pd, Pt, Rh, Ir and Ni) with poison resistant coinage metal hosts (Cu, Ag, Au), such that individual PGM atoms are dispersed at the atomic limit forming single atom alloys (SAAs). We show that compared to the pure metals, CO exhibits lower binding strength on the majority of SAAs studied, and we use kinetic Monte Carlo simulation to obtain relevant temperature programed desorption spectra, which are found to be in good agreement with experiments. Additionally, we consider the effects of CO adsorption on the structure of SAAs. We calculate segregation energies which are indicative of the stability of dopant atoms in the bulk compared to the surface layer, as well as aggregation energies to determine the stability of isolated surface dopant atoms compared to dimer and trimer configurations. Our calculations reveal that CO adsorption induces dopant atom segregation into the surface layer for all SAAs considered here, whereas aggregation and island formation may be promoted or inhibited depending on alloy constitution and CO coverage. This observation suggests the possibility of controlling ensemble effects in novel catalyst architectures through CO-induced aggregation and kinetic trapping.

Investigation of Degradation Heterogeneities in PEMFC Stack Aged under Reformate Coupling In Situ Diagnosis, Post-Mortem Ex Situ Analyses and Multi-Physic Simulations

Proton Exchange Membrane Fuel cells (PEMFCs) durability of stacks operated under reformate is investigated with a special focus on the heterogeneity of aging. During an aging test at constant load, the local performances were investigated in situ using a segmented circuit board and a specific CO poisoning diagnostic tool based on the transition from pure hydrogen to reformate containing carbon monoxide. The heterogeneities analyses are supported with multi-physic simulations which highlight the heterogeneous CO coverage along the anode, as well as the competition between both electrodes leading to non-monotonous current density profiles. At the end of life, electrochemical and transmission electron microscopy analyses were performed on three characteristic zones (air inlet/H2 outlet, middle and air outlet/H2 inlet) of the Membrane Electrode Assembly (MEA). These experimental investigations put in evidence that the cathode outlet aged more severely than the cathode inlet, while more CO tolerance was lost at the anode outlet. The degradation by the electrochemical Ostwald ripening mechanism of the Pt3Co nanoparticles at the cathode outlet is suspected to pollute the ionomer, leading to the observed accelerating performance losses. Finally, optimized MEAs have been designed to mitigate the suspected degradation mechanisms, and tested at stack level demonstrating a clear durability improvement.

Modification of Surface Reactivity by CO: Effects on Decomposition and Polymerization of Acetaldehyde on Ru(0001)

The adsorption and reaction of acetaldehyde on the clean and CO pre-covered Ru(0001) surfaces have been investigated using temperature programmed desorption method. On the clean Ru(0001) surface, the decomposition of acetaldehyde is the main reaction channel, with little polymerization occurring. However, on the CO pre-covered Ru(0001) surface, the decomposition of acetaldehyde is inhibited considerably with increasing CO coverage. Whereas, the polymerization occurs efficiently, especially at high CO coverage (θCO>0.5 ML), which is strongly CO coverage dependent. Combined with previous studies, the well-ordered hexagonal structure of CO layer formed on the Ru(0001) surface at high CO coverage that matches the configuration of paraldehyde is likely to be the origin of this remarkable phenomenon.

Catalytic CO Oxidation by CO-Saturated Au Nanoparticles Supported on CeO2: Effect of CO Coverage

Understanding the reaction mechanism and the nature of the reactive species of heterogeneous catalysts under reaction conditions is the first step in the design of more consistent, reliable, and practical catalysts. We used density functional theory (DFT) calculations to study the mechanism of CO oxidation catalyzed by CeO2-supported Au nanoparticles (NPs) under reaction conditions by considering the sequential CO adsorption onto and CO saturation of Au NPs. We found that the Au9 NPs supported by CeO2(100) and CeO2(111) bind as many as eight or four CO molecules, respectively. The last-bound CO molecule opens the fast CO oxidation pathway. The CO oxidation pathways constructed on both systems show that the reaction occurs at the Au–CeO2 interface via the Mars–van Krevelen mechanism. We found that the most important O–C–O-type intermediate was spontaneously formed at the Au–CeO2(100) interface upon the sequential binding of CO molecules onto the Au NPs. The reaction pathway therefore becomes relatively sim...

Lithium-functionalized germanene: A promising media for CO2 capture

Density functional theory (DFT) is employed to investigate the interactions of CO2 gas molecules with pristine and lithium-functionalized germanene. It is discovered that although a single CO2 molecule is weakly physisorbed on pristine germanene, a significant improvement on its adsorption energy is found by utilizing Li-functionalized germanene as the adsorbent. Excitingly, the moderate adsorption energy at high CO2 coverage secures an easy release step. Moreover, the structure of Li-functionalized germanene can be fully recovered after removal of CO2 gas molecules. Our results suggest that Li-functionalized germanene show promise for CO2 sensing and capture with a storage capacity of 12.57 mol/kg.

Steric effect in CO oxidation on Pt(111).

We present experimental evidence showing that the rate of CO oxidation on Pt(111) depends strongly on the geometry of an incident O2 molecule. The O2 sticking probability and the CO2 production rate on CO-covered Pt(111) surfaces during the alignment-controlled O2 beam irradiation were simultaneously monitored at a surface temperature of 330 K. The results indicate that, at the translational energy of 0.1-0.2 eV and at the CO coverage of <0.4 monolayers, both O2 adsorption and CO oxidation proceed exclusively when the O2 molecular axis is nearly parallel to the surface.

Optimum Cu nanoparticle catalysts for CO2 hydrogenation towards methanol

Understanding the mechanism of CO2 hydrogenation to methanol is important in the context of renewable energy storage from societal and technological point of view. We use density functional theory calculations to study systematically the effect of the size of Cu clusters on the binding strengths of reactants and reaction intermediates as well as the activation barriers for the elementary reaction steps underlying CO2 hydrogenation. All the elementary reaction barriers exhibit linear scaling relationships with CO and O adsorption energies. Used in microkinetics simulations, we predict that medium-sized Cu19 clusters exhibit the highest CO2 hydrogenation activity which can be ascribed to a moderate CO2 coverage and a low CO2 dissociation barrier. The nanoscale effect is evident from the strong variation of CO and O adsorption energies for clusters with 55 or less Cu atoms. The reactivity of larger clusters and nanoparticles is predicted to depend on surface atoms with low coordination number. Optimum activity is correlated with the bond strength of reaction intermediates determined by the d-band center location of the Cu clusters and the extended surfaces. The presented size-activity relations provide useful insight for the design of better Cu catalysts with maximum mass-specific reactivity for CO2 hydrogenation performance.

Stability and Effects of Subsurface Oxygen in Oxide-Derived Cu Catalyst for CO2 Reduction

Oxide-derived copper (OD-Cu) catalysts are promising candidates for the electrochemical CO2 reduction reaction (CO2RR) due to the enhanced selectivity toward ethylene over methane evolution, which has been linked to the presence of subsurface oxygen (Osb). In this work, Osb is investigated with theoretical methods. Although Osb is unstable in slab models, it becomes stabilized within a “manually” reduced OD-Cu nanocube model which was calculated by self-consistent charge density functional tight binding (SCC-DFTB). The results obtained with SCC-DFTB for the full nanocube were confirmed with subcluster models extracted from the nanocube, calculated with both density functional theory (DFT) and SCC-DFTB. The higher stability of Osb in the nanocube is attributed to the disordered structure and greater flexibility. The adsorption strength of CO on Cu(100) is enhanced by Osb withdrawing electron density from the Cu atom, resulting in reduction of the σ-repulsion. Hence, the coverage of CO may be increased, fac...

Mechanism of Cobalt-Catalyzed CO Hydrogenation: 1. Methanation.

The mechanism of CO hydrogenation to CH4 at 260 °C on a cobalt catalyst is investigated using steady-state isotopic transient kinetic analysis (SSITKA) and backward and forward chemical transient kinetic analysis (CTKA). The dependence of CHx residence time is determined by 12CO/H2 → 13CO/H2 SSITKA as a function of the CO and H2 partial pressure and shows that the CH4 formation rate is mainly controlled by CHx hydrogenation rather than CO dissociation. Backward CO/H2 → H2 CTKA emphasizes the importance of H coverage on the slow CHx hydrogenation step. The H coverage strongly depends on the CO coverage, which is directly related to CO partial pressure. Combining SSITKA and backward CTKA allows determining that the amount of additional CH4 obtained during CTKA is nearly equal to the amount of CO adsorbed to the cobalt surface. Thus, under the given conditions overall barrier for CO hydrogenation to CH4 under methanation condition is lower than the CO adsorption energy. Forward CTKA measurements reveal that O hydrogenation to H2O is also a relatively slow step compared to CO dissociation. The combined transient kinetic data are used to fit an explicit microkinetic model for the methanation reaction. The mechanism involving direct CO dissociation represents the data better than a mechanism in which H-assisted CO dissociation is assumed. Microkinetics simulations based on the fitted parameters confirms that under methanation conditions the overall CO consumption rate is mainly controlled by C hydrogenation and to a smaller degree by O hydrogenation and CO dissociation. These simulations are also used to explore the influence of CO and H2 partial pressure on possible rate-controlling steps.

(Keynote) Experimental Considerations for Electrocatalytic CO2 Reduction

Electrocatalytic reduction of CO2 has the potential to convert CO2 into carbon-based fuels by using renewable energy. While a wide range of electrocatalytic materials have been investigated, the process is still limited by poor reaction selectivity or large overpotentials. Hence many have studied the effects of surface oxides, crystal facets, and nanoparticles on the activity and selectivity of CO2 reduction. Others have also shown that the reaction is sensitive to conditions such as temperature, CO2 pressure, electrolyte buffer concentration and electrode porosity. These effects mean that it can be challenging to determine the underlying cause for differences in intrinsic catalytic behaviour [1,2], and thus it is important to understand the effect of experimental conditions on CO2reduction. Firstly, we will review the literature and our own experimental work which clearly highlight the importance of interfacial pH on the reaction [2-4]. It is well known that in weak buffers such as KHCO3, the pH at the surface of the cathode is significantly higher than the bulk due to the hydrogen evolution and CO2 reduction reactions. By conducting experiments over a range of KHCO3 concentrations (and thus different interfacial pH values), it is clear that this alters the selectivity and activity of CO2 reduction. As the hydrodynamics at the cathode surface will also alter interfacial pH, we have examined the effect of hydrodynamics on the CO2 reduction reaction using a Cu rotating cylinder electrode [5]. Given that the enhanced mass transport will also increase the CO2 concentration at the electrode surface [6], it seems clear that mass transfer effects should influence the reaction selectivity. We confirm that this is indeed an important factor and suggest that increasing mass transport not only decreases the interfacial pH (closer to bulk values) but also decreases the surface coverage of CO on the cathode (a key immediate during CO2 reduction), which ultimately lowers the current going to the CO2reduction reaction. As these experiments revealed the importance of both KHCO3 concentration and mass transport, we developed a numerical model to predict how the bulk electrolyte composition changes during long term electrolysis experiments. This model was validated against experiment data and shows that changes in the bulk electrolyte (ionic resistance, pH, CO2-electrolyte equilibria) can occur over the course of long-term electrolysis experiments. These changes can complicate the interpretation of long-term electrode behaviour as well as the control of the electrochemical process. From these findings, we suggest a range of strategies to improve the experimental aspects of electrochemical CO2reduction investigations. [1] A.S. Hall, Y. Yoon, A. Wuttig, Y. Surendranath, Mesostructure-Induced Selectivity in CO2Reduction Catalysis, Journal of the American Chemical Society 137 (2015) 14834-14837. [2] R. Kas, R. Kortlever, H. Yılmaz, M.T.M. Koper, G. Mul, Manipulating the Hydrocarbon Selectivity of Copper Nanoparticles in CO2Electroreduction by Process Conditions, ChemElectroChem 2 (2015) 354-358. [3] K.J.P. Schouten, E. Pérez Gallent, M.T.M. Koper, The influence of pH on the reduction of CO and to hydrocarbons on copper electrodes, Journal of Electroanalytical Chemistry 716 (2014) 53-57. [4] A.S. Varela, M. Kroschel, T. Reier, P. Strasser, Controlling the selectivity of CO2electroreduction on copper: The effect of the electrolyte concentration and the importance of the local pH, Catalysis Today 260 (2016) 8-13. [5] C.F.C. Lim, D.A. Harrington, A.T. Marshall, Effects of mass transfer on the electrocatalytic CO2 reduction on Cu, Electrochimica Acta (2017) in press. [6] N. Gupta, M. Gattrell, B. MacDougall, Calculation for the cathode surface concentrations in the electrochemical reduction of CO2 in KHCO3solutions, Journal of Applied Electrochemistry 36 (2006) 161-172. [7] K. Hara, A. Tsuneto, A. Kudo, T. Sakata, Electrochemical Reduction of CO2 on a Cu Electrode under High Pressure: Factors that Determine the Product Selectivity, Journal of The Electrochemical Society 141 (1994) 2097-2103.

Role of CO* as a Spectator in CO2 Electroreduction on RuO2

RuO2-based electrocatalysts are found to be active at low overpotential toward direct electrochemical reduction of CO2 to formic acid and methanol. RuO2 can circumvent the thermodynamic bottleneck resulting from the scaling relations observed on metallic electrocatalyst, by utilizing an alternate pathway through oxygen-coordinated intermediates. Employing density functional theory based computational electrocatalysis models we show adsorbate–adsorbate interaction effects for adsorbates and reaction intermediates on the RuO2(110) surface are large and impactful to the reaction thermodynamics. We studied binding energy amendment due to adsorbate interaction (steric and electronic) with varying coverage of CO* spectators on the catalyst surface. Implications on the reaction pathways help us rationalize differences in experimentally observed carbonaceous product mix and suppression of the hydrogen evolution reaction (HER). We show that a moderate CO* coverage (∼50%) is necessary for obtaining methanol as a pr...

Driving CO2 to a Quasi-Condensed Phase at the Interface between a Nanoparticle Surface and a Metal-Organic Framework at 1 bar and 298 K.

We demonstrate a molecular-level observation of driving CO2 molecules into a quasi-condensed phase on the solid surface of metal nanoparticles (NP) under ambient conditions of 1 bar and 298 K. This is achieved via a CO2 accumulation in the interface between a metal-organic framework (MOF) and a metal NP surface formed by coating NPs with a MOF. Using real-time surface-enhanced Raman scattering spectroscopy, a >18-fold enhancement of surface coverage of CO2 is observed at the interface. The high surface concentration leads CO2 molecules to be in close proximity with the probe molecules on the metal surface (4-methylbenzenethiol), and transforms CO2 molecules into a bent conformation without the formation of chemical bonds. Such linear-to-bent transition of CO2 is unprecedented at ambient conditions in the absence of chemical bond formation, and is commonly observed only in pressurized systems (>105 bar). The molecular-level observation of a quasi-condensed phase induced by MOF coating could impact the future design of hybrid materials in diverse applications, including catalytic CO2 conversion and ambient solid-gas operation.

CO adsorption on Pd(100) studied by multimodal ambient pressure X-ray photoelectron and infrared reflection absorption spectroscopies

The adsorption of CO on Pd(100) was investigated using simultaneous ambient pressure X-ray photoelectron spectroscopy (APXPS) and infrared reflection absorption infrared spectroscopy (IRRAS). The measurements were performed as a function of CO partial pressures from ultra-high vacuum to 0.5 Torr. Total CO coverages estimated from the complementary APXPS and IRRAS measurements are in good agreement. A signal for atop CO, which is uncommon for Pd(100), was observed in the IRRAS data and was used to identify the C 1 s binding energy of this species. Discerning this binding configuration of CO on the Pd(100) surface at elevated pressures has significance for catalytic reactions involving CO, where bridging CO is often the only configuration considered. We also detail the combined APXPS/IRRAS instrumentation and discuss ways to improve these multimodal measurements, which should have wide applicability across many areas of surface and interface science.

CO Poisoning and CO Hydrogenation on the Surface of Pd Hydrogen Separation Membranes

To understand how CO inhibits hydrogen transport across Pd membranes, a 25-μm-thick Pd foil membrane was monitored by infrared-reflection absorption spectroscopy (IRAS) during exposure to H2/CO gas mixtures while the rate of hydrogen permeation across the membrane was measured simultaneously in the 373–533 K temperature range. As the coverage of CO on the membrane surface increases with increasing CO concentration and decreasing temperature, the rate of hydrogen permeation across the membrane decreases. However, in addition to adsorbing on the membrane surface, CO reacts with H2 to form surface-adsorbed methylene (CH2) species and methane in the gas phase. The coverage of methylene increases with decreasing temperature and, therefore, the strong poisoning effect of CO at low temperatures may be due to both CO and methylene species blocking H2 dissociation sites on the membrane surface. The activity and selectivity of the Pd membrane for CO methanation is much higher than expected from previous studies and...

Polarization-Dependent Infrared Spectroscopy of Adsorbed Carbon Monoxide To Probe the Surface of a Pd/Cu(111) Single-Atom Alloy

Single-atom alloys can be formed by depositing a low coverage of active metal onto the surface of another metal. Few experimental techniques permit verification that the deposited metal exists as single-atom sites on the host metal surface. Here we use polarization-dependent reflection absorption infrared spectroscopy (PD-RAIRS) to characterize the surface of a Pd/Cu(111) single-atom alloy through the use of CO as a probe molecule. In the presence of 1 × 10–2 Torr of CO at 300 K, significant coverages of CO are only achieved when Pd is present on the surface. The Pd coverage at the surface is determined with RAIRS from the C–O stretch peak areas while the total amount of Pd in the first few atomic layers is measured with Auger electron spectroscopy. Isolated Pd atoms in Cu(111) are revealed with RAIRS by the C–O stretch peak of CO bound on top of a Pd atom. The appearance of C–O stretch peaks due to bridge-site CO occurs at Pd coverages where Pd atoms start to agglomerate. An isosteric heat of adsorption ...

An efficient method in manipulating CO coverage dissociated from small organic molecules on the Pt electrode surface

Fuel cells are environmentally friendly energy systems with high energy efficiency, which are expected to play important roles in the sustainable society. However, CO-caused poisoning catalysts have been important problems in fuel cells, which hinder the practical applications of fuel cells. In this study, we studied the process of HCHO dissociation on the Pt electrode under different potentials using the electrochemical cell which can control the potential and replace the solution efficiently. The experimental results showed that with the positive shift of potential, the CO coverage on Pt due to the dissociation of HCHO slightly decreases from 71% at −0.2 V to 60% at 0.25 V. A sharp decline of the coverage of CO appears at 0.3 V. The coverage of CO is only 8%, which is far less than 64% at the open-circuit potential (ocp). The experimental results indicated that we can apply different control potential to manipulate the CO coverage and thus propose a new method of operation to reduce the CO poisoning. Verification experiments in formaldehyde showed that the initial oxidation current was 3×10−4 A, close to the peak current of 4×10−4 A and far more than the current of 3×10−5 A at the ocp experiment, after the addition of formaldehyde with potential control at 0.35 V for 300 s. Adding formaldehyde with potential control at 0.35 V can reduce the poisoning effect of CO on the catalyst effectively. This result may practically be applied in the commercial fuel cells.

Tuning Electrocatalytic Activity of Ultrathin Pd Shells: CO2 to Fuels

It is well established that thin metal layers on a foreign support can exhibit very distinctive electrocatalytic activity with respect to bulk electrodes. In the case of d­-metals, changes in reactivity can be rationalised in terms of the so-called ligand or strain (also known as geometric) effects. Although is commoly argued that ligand effects are rather short range (sub-monolayer to few atomic layers), it is notoriusly difficult to experimentally differentiate the contributions from these two phenomena. In this contribution, we shall explore ligand and strain effects on the electrocatalytic properties of Au-Pd core-shell nanoparticles towards CO2 reduction to fuels. The electrochemical properties and product generation are probed by off-line 1H NMR, differential electrochemical mass spectrometry (DEMS), on-line Mass spectrometry (OLEMS) and in-situ FTIR. Thin Pd shells were grown onto 20 nm Au nanoparticles employing a colloidal synthesis method at low temperatures, generating continuous shells with tuneable mean thickness between 1.3±0.1 (CS1) and 9.9±1.1 nm (CS10). Selected area electron diffraction patterns revealed that the effective Pd strain decreases from 3.5 to less than 1% in this thickness range, which is consistent with strain relaxtion mechanisms at Au {111} surfaces. DEMS was used to calculate the faradaic efficiency associated with the CO2 reduction vs hydrogen evolution at the core-shell nanostructures supported on a porous carbon layer. The data show that over 90% of the faradaic charge in the range between 0.0 to -0.5 V vs RHE is consumed in CO2 conversion at CS1 nanoparticles, as opposed to approximately 40% in the case of CS10. The analysis of the electrolyte solution employing 1H NMR revealed the formation of HCOO- only in the case of CS10 over a narrow potential range centred at -0.4 V, with faradaic efficiencies close to 30%. Furthermore, CH4 and C2H6 were also detected using OLEMS at potentials as negative as -0.7 V at the CS10 nanoparticles. No products in solution were detected In the case of CS1, indicating that CO is the main product generated over the entire potential range. The contrast in reaction pathway and electrocatalytic performance are rationalised in terms of the CO affinity to the Pd nanoshells. To probe this, in-situ FTIR studies were performed revealing that the potential dependence of the adsorbed C-O stretching band (stark slope) is significantly weaker on CS1 in comparison to CS10. Furthermore, the effective CO coverage increases with increasing Pd thickness, reaching values reported for polycrystalline bulk Pd electrodes in the case of CS10. These results show that CO has a significantly weaker binding to strain Pd shells (CS1). Finally DFT calculations are used to estimate the contributions of the so-called ligand and strain effects on the local density of states of the Pd d-band. The calculations strongly suggest that the key parameters contributing to the change in mechanism is the effective lattice strain.

Mechanisms of Hydrogen-Assisted CO2 Reduction on Nickel.

Mechanistic details of catalytic reactions are critical to the development of improved catalysts. Here, we perform high quality Born-Oppenheimer molecular dynamics simulations of the reaction mechanisms associated with hydrogen-assisted CO2 reduction on Ni(110). The simulation results show direct theoretical evidence for both associative and redox mechanisms in the reaction of atomic hydrogen with CO2. Because H2 is dissociatively chemisorbed on Ni(110) with nearly unit probability, the mechanisms we find are also relevant to the reverse water-gas shift reaction (H2 with adsorbed CO2). Furthermore, we provide the first real-time demonstration of both Eley-Rideal (ER) and hot atom (HA) mechanisms when H impinges on adsorbed CO2, and we show that both occur even for low kinetic energies. The trade-off between ER or HA mechanisms is found to be strongly dependent on CO2 coverage. The results are compared with recent gas/surface measurements.

Quantitative and Atomic-Scale View of CO-Induced Pt Nanoparticle Surface Reconstruction at Saturation Coverage via DFT Calculations Coupled with in Situ TEM and IR.

Atomic-scale insights into how supported metal nanoparticles catalyze chemical reactions are critical for the optimization of chemical conversion processes. It is well-known that different geometric configurations of surface atoms on supported metal nanoparticles have different catalytic reactivity and that the adsorption of reactive species can cause reconstruction of metal surfaces. Thus, characterizing metallic surface structures under reaction conditions at atomic scale is critical for understanding reactivity. Elucidation of such insights on high surface area oxide supported metal nanoparticles has been limited by less than atomic resolution typically achieved by environmental transmission electron microscopy (TEM) when operated under realistic conditions and a lack of correlated experimental measurements providing quantitative information about the distribution of exposed surface atoms under relevant reaction conditions. We overcome these limitations by correlating density functional theory predictions of adsorbate-induced surface reconstruction visually with atom-resolved imaging by in situ TEM and quantitatively with sample-averaged measurements of surface atom configurations by in situ infrared spectroscopy all at identical saturation adsorbate coverage. This is demonstrated for platinum (Pt) nanoparticle surface reconstruction induced by CO adsorption at saturation coverage and elevated (>400 K) temperature, which is relevant for the CO oxidation reaction under cold-start conditions in the catalytic convertor. Through our correlated approach, it is observed that the truncated octahedron shape adopted by bare Pt nanoparticles undergoes a reversible, facet selective reconstruction due to saturation CO coverage, where {100} facets roughen into vicinal stepped high Miller index facets, while {111} facets remain intact.