Terrace Sites Research Articles

Modeling stepped Pt/water interfaces at potential of zero charge with ab initio molecular dynamics.

It is worth understanding the potentials of zero charge (PZCs) and structures of stepped metal/water interfaces, because for many electrocatalytic reactions, stepped surfaces are more active than atomically flat surfaces. Herein, a series of stepped Pt/water interfaces are modeled at different step densities with ab initio molecular dynamics. It is found that the structures of Pt/water interfaces are significantly influenced by the step density, particularly in regard to the distribution of chemisorbed water. The step sites of metal surfaces are more preferred for water chemisorption than terrace sites, and until the step density is very low, water will chemisorb on the terrace. In addition, it is revealed that the PZCs of stepped Pt/water interfaces are generally smaller than that of Pt(111), and the difference is mainly attributed to the difference in their work function, providing a simple way to estimate the PZCs of stepped metal surfaces. Finally, it is interesting to see that the Volta potential difference is almost the same for Pt/water interfaces with different step densities, although their interface structures and magnitude of charge transfer clearly differ.

Adsorption and adhesion energies of n-Decane on the Pt(111) surface by calorimetry

The heat of adsorption of n-decane molecularly adsorbed on Pt(111) at 150 K was measured by single-crystal adsorption calorimetry (SCAC). The heat of adsorption was initially ∼152 kJ/mol on terrace sites up to a coverage of Θ = 0.045 ML . Previous TPD measurements of the desorption energies of shorter n-alkanes (C1 to C6) on Pt(111) terraces showed a linear increase with chain length which predicts a desorption energy for n-decane in very good agreement with this new result. A heat of 169 kJ/mol was measured below 0.004 ML and attributed to defect sites, probably step edges. At coverages above Θ = 0.27 ML (∼3 molecular layers), the multilayer heat of adsorption was constant at ∼85 kJ/mol. Using the heat of adsorption versus coverage at 150 K up through this bulk-like multilayer, the adhesion energy per unit area of liquid n-decane on Pt(111) terraces at room temperature was estimated to be 0.148 J/m2. This is very similar to the value estimated for liquid n-hexane on Pt(111) from TPD energies, which shows that while adsorption energy increases nearly proportional to the number of CH2 plus CH3 groups, as the adhesion energy is a per unit area value, it remains nearly constant (0.15 J/m2) between hexane and decane.

Reversible transformation between terrace and step sites of Pt nanoparticles on titanium under CO and O2 environments

Understanding the dynamic evolution of active sites of supported metal catalysts during catalysis is fundamentally important for improving its performance, which attracts tremendous research interests in the past decades. There are two main surficial structures for metal catalysts: terrace sites and step sites, which exhibit catalytic activity discrepancy during catalysis. Herein, by using in situ transmission electron microscopy and in situ Fourier transform infrared spectroscopy (FTIR), the transformation between surface terrace and step sites of Pt-TiO2 catalysts was studied under CO and O2 environments. We found that the {111} step sites tend to form at {111} terrace under O2 environment, while these step sites prefer to transform into terrace under CO environment at elevated temperature. Meanwhile, quantitative ratios of terrace/step sites were obtained by in situ FTIR. It was found that this transformation between terrace sites and step sites was reversible during gas treatment cycling of CO and O2. The selective adsorption of O2 and CO species at different sites, which stabilized the step/terrace sites, was found to serve as the driving force for active sites transition by density functional theory calculations. Inspired by the in situ results, an enhanced catalytic activity of Pt-TiO2 catalysts was successfully achieved through tuning surface-active sites by gas treatments.

Key Role of a-Top CO on Terrace Sites of Metallic Pd Clusters for CO Oxidation.

Pd-based catalysts are the most widely used for CO oxidation because of their outstanding catalytic activity and thermal stability. However, fundamental understanding of the detailed catalytic processes occurring on Pd-based catalysts under realistic conditions is still lacking. In this study, we investigated CO oxidation on metallic Pd clusters supported on Al2 O3 and SiO2 . High-angle annular dark-field scanning transmission electron microscopy revealed the formation of similar-sized Pd clusters on Al2 O3 and SiO2 . In contrast, CO chemisorption analysis indicated a gradual change in the dispersion of Pd (from 0.79 to 0.2) on Pd/Al2 O3 and a marginal change in the dispersion (from 0.4 to 0.24) on Pd/SiO2 as the Pd loading increased from 0.27 to 5.5 wt %; these changes were attributed to differences in the metal-support interactions. Diffuse reflectance infrared Fourier-transform spectroscopy revealed that fewer a-top CO species were present in Pd supported on Al2 O3 than those in Pd supported on SiO2 , which is related to the morphological differences in the metallic Pd clusters on these two supports. Despite the different dispersion profiles and surface characteristics of Pd, O2 titration demonstrated that linearly bound CO (with an infrared signal at 2090 cm-1 ) reacted first with oxygen in the case of CO-saturated Pd on Al2 O3 and SiO2 , which suggests that a-top CO on the terrace site plays an important role in CO oxidation. The experimental observations were corroborated by periodic density functional calculations, which confirmed that CO oxidation on the (111) terrace sites is most plausible, both kinetically and thermodynamically, compared to that on the edge or corner sites. This study will deepen the fundamental understanding of the effect of Pd clusters on CO oxidation under reaction conditions.

Insights into the Hydrogenolysis Mechanism of Diphenyl Ether over Cl-Modified Pt/γ-Al2O3 Catalysts by Experimental and Theoretical Studies

Catalytic hydrogenolysis is an efficient method for converting lignin-derived aryl ethers into monoaromatic products by cleaving the C–O bond and maintaining the phenyl rings. However, it is difficult to obtain aromatics with high selectivity because ring hydrogenation proceeds in parallel. Herein, we showed that a Cl-modified Pt/γ-Al2O3 catalyst exhibited higher selectivity for aromatics (91.6%) compared to unmodified Pt/γ-Al2O3 (3.9%) in C–O bond cleavage of diphenyl ether (DPE, 4-O-5 linkage in lignin). Characterization of the catalysts and density functional theory (DFT) calculations indicated that the Cl species preferred to localize at the terrace sites of Pt nanoparticles (NPs). Due to the decrease in the number of active sites, the Cl-modified Pt/γ-Al2O3 catalyst exhibited low activity for 2-propanol dehydrogenation, and thus the catalytic activity for the hydrogenation of aromatic products was suppressed. On the other hand, DPE adsorbed at the low coordination site, which caused the phenyl rings to move away from the metal surface; this configuration was unfavorable for the hydrogenation reaction. According to DFT calculations, the high selectivity for benzene was mainly attributed to the lower energy barrier for C–O bond cleavage of phenol at the low-coordination sites.

On the earliest Acheulean in Britain: first dates and in-situ artefacts from the MIS 15 site of Fordwich (Kent, UK).

Northern Europe experienced cycles of hominin habitation and absence during the Middle Pleistocene. Fluvial gravel terrace sites in the east of Britain and north of France provide a majority of the data contributing to this understanding, mostly through the presence or absence of stone-tool artefacts. To date, however, relatively few sites have been radiometrically dated, and many have not been excavated in modern times, leading to an over-reliance on selectively sampled and poorly dated lithic assemblages. This includes Fordwich (Kent, UK), where over 330 bifaces were discovered through industrial quarrying in the 1920s. Here, we present the first excavation and dating of artefacts discovered in situ at Fordwich, alongside their technological analysis and relationship to those previously recovered. The site is demonstrated to retain deposits of Lower Palaeolithic artefacts, with 251 flakes, scrapers and cores identified to date. Infrared-radiofluorescence (IR-RF) dating of feldspar reveals 112 artefacts to have come from levels dating to at least 570 ± 36 to 513 ± 30 thousand years ago (ka) and are most plausibly assigned to an MIS 14 deposition, with artefacts produced during MIS 15 (approx. 560–620 ka). Indeed, these IR-RF samples provide minimum ages for artefacts. Combined with evidence from exposures linked to the original quarrying activities, a similar MIS 15 age is suggested for the more than 330 handaxe artefacts discovered in the 1920s. The remaining excavated artefacts come from levels dated to between 347 ± 22 and 385 ± 21 ka (MIS 10 or 11), with this later age interpreted to reflect post-MIS 14 deposition by substrate gullying and solifluction. These data demonstrate Fordwich to be one of the earliest Palaeolithic sites in northwestern Europe, and to retain the only large Acheulean handaxe assemblage directly dated to pre-MIS 13. Thus, Fordwich is determined to be a crucial piece of the pre-Anglian Palaeolithic puzzle in northern Europe.

Selective Hydration of Rutile TiO2 as a Strategy for Site-Selective Atomic Layer Deposition.

The feasibility of a site-selective hydration strategy that enables site-selective atomic layer deposition (ALD) is investigated among four rutile TiO2 facets [(110), (100), (101) and (001)] and their most prevalent step edges. First-principles simulations of asymmetric slab models were utilized to create accurate representations of pristine terrace and step edge sites. The adsorption free energies for molecular and dissociative adsorption of H2O were calculated to evaluate this strategy as a viable route to step edge selectivity. We predict that selective hydroxylation is possible on the 110 and 001 step edges and further computationally evaluate three metalorganic ALD precursors for their compatibility with the selective hydration strategy. Experimental evidence for delayed nucleation of ALD on rutile (001), (110), and (100) TiO2 single crystals corroborates predictions of the dehydration of the surface and suggests the possibility of site-selective ALD.

Controllable Surfactant‐free Synthesis of Colloidal Platinum Nanocuboids Enabled by Bromide Ions and Carbon Monoxide

AbstractPt nanoparticles enclosed by Pt{100} facets show unique properties in electrocatalysis. However, a convenient, cost‐effective, controllable and scalable synthesis of surface clean Pt colloidal nanocuboids remains a big challenge. In this work, small platinum nanocubes with controllable size ranging from 3.4 to 7.1 nm and nanocuboids with tuneable length‐to‐width aspect ratios were synthesized under the 10 %CO/90 %He atmosphere, by controlling the proportion of KBr and Pt precursors and the concentration of the platinum precursor in ethylene glycol. The exposed Pt{100} terrace sites of the synthesize materials were not only identified by the transmission electron microscopic images but also by the electrochemical adsorption/desorption of hydrogen during cyclic voltammograms. In addition, the exposed Pt{100} domains were quantitatively measured by the electrochemical adsorption/desorption of germanium, proving the formation of nanocuboids. Finally, the synthesized Pt nanocubes were applied to the oxygen reduction reaction and the electrochemical oxidation of methanol, showing a big potential in electrocatalysis.

Evidence of undissociated CO2 involved in the process of C-H bond activation in dry reforming of CH4

We investigate here systematically C-H bond activation mechanism on Pt/MgO with O2, H2O and CO2, and find that dry reforming of CH4 (DRM) experiences a weak activity compared with reforming or partial oxidation of CH4. Pressure dependence shows negligible effect of CO determined within a broad CO pressure regime (<10 kPa at high-pressure CH4/CO2 (20.3 kPa) and <0.3 kPa at low-pressure CH4/CO2 (0.8 kPa)) and competitive adsorption between CH4 and CO2 (0.8 kPa), suggesting that CO2 is involved in CH4 activation as an entire molecule. Based on established Langmuir-Hinshelwood model, reaction between adsorbed CH4 and CO2 to yield formate and methyl species was kinetically relevant. Both CO2 and CH4 derivatives are the most abundant surface intermediates, being confirmed by in situ FTIR and quasi-in-situ XPS. The oxidizability of oxidant was quantitatively evaluated; CO2 has the weakest oxidizability, probably making DRM less active. DRM is structure-sensitive with terrace site of Pt as active component. The influence of reverse water–gas shift was dominant in modifying selectivity. This work will certainly reconcile contradictories on CH4 activation mechanism and push the industrial application of CH4 forward.

Size-dependent activity of supported Ru catalysts for ammonia synthesis at mild conditions

Ammonia (NH3) synthesis is a structure-sensitive reaction, where a minute variation of catalyst structure would lead to a dramatic change of activity. To date, the roles of Ru size on NH3 synthesis still remain elusive, and it remains a major challenge. Herein, a series of Ru catalysts with sizes ranging from 1.4 to 5.0 nm were prepared by colloidal Ru deposition, which allows the investigation of size influence on NH3 synthesis. Through analyses of the geometric and electronic properties of variable-sized Ru particles, it shows that the reduction of Ru particle size could increase the proportion of corner sites while decrease that of terrace sites, which can decrease the work function and thus promote N2 for its activation. Isotopic investigations show that the decrease of dissociative contribution but the increase of associative contribution as Ru particle size was decreased from 5.0 to 1.4 nm. Meanwhile, the NH3 synthesis rate increases when the size of Ru catalysts decreases from 5.0 to 1.4 nm. Using a suite of elaborate characterizations, we have observed that 1.4 nm Ru nanoclusters (NCs) with ample corner sites are conducive to activate N2 via an associative route. As a result, the 1.4 nm Ru NCs catalyst shows the highest NH3 synthesis rate (up to 17.13 mmolNH3 gcat−1h−1) at 400 ℃ and 1 MPa.

Microscopic EDL structures and charge-potential relation on stepped platinum surface: Insights from the ab initio molecular dynamics simulations.

The microstructural features and charge-potential relation of an electric double layer (EDL) at a stepped Pt(553)/water interface are investigated using ab initio molecular dynamics simulation. The results indicate that the chemisorbed O-down water molecules gather at the (110) step sites, while the (111) terrace sites are covered by the H-down water molecules, which greatly weakens the push-back effect of interface water on the spillover electrons of the stepped surface and, therefore, results in a much more positive potential of zero charge (PZC) than the extended low-index Pt surfaces. It is further revealed that around the PZC, the change in the surface charge density is dominated by the change in the coverage of chemisorbed water molecules, while EDL charging is the main cause of the change in the surface charge density at potential away from the PZC, thus leading to an S-shaped charge-potential relation and a maximum interface capacitance around PZC. Our results make up for the current lack of the atomic-scale understanding of the EDL microstructures and charge-potential relation on the real electrode surfaces with plentiful step and defect sites.

C2H2 semi-hydrogenation over Cu catalysts: Revealing the influence of Cu active site types on the catalytic performance

The type of active site is a critical factor to determine catalytic performance. Here, DFT calculations are employed to systematically investigate the influence of Cu active site type on C2H2 semi-hydrogenation. Generalized coordination number (GCN) from 2.5 to 7.5 is used as a descriptor to characterize the type of Cu active site, including the corner, defect, step, and terrace sites. Our results showed that GCN can differentiate the type of Cu active site. C2H2 semi-hydrogenation performance closely depends on the type of Cu active site and GCN. Among them, Cu defect site with the moderate GCN of 4.8 is screened out to exhibit the best catalytic performance, which significantly inhibits green oil formation, and presents excellent C2H4 activity and selectivity. This work provides a basis for rational design Cu catalysts with excellent performance by adjusting the type of active site and GCN in C2H2 semi-hydrogenation.

Catalytic resonance of ammonia synthesis by simulated dynamic ruthenium crystal strain.

Ammonia affords dense storage for renewable energy as a fungible liquid fuel, provided it can be efficiently synthesized from hydrogen and nitrogen. In this work, the catalysis of ammonia synthesis was computationally explored beyond the Sabatier limit by dynamically straining a ruthenium crystal (±4%) at the resonant frequencies (102 to 105+ Hz) of N2 surface dissociation and hydrogenation. Density functional theory calculations at different strain conditions indicated that the energies of NHx surface intermediates and transition states scale linearly, allowing the description of ammonia synthesis at a continuum of strain conditions. A microkinetic model including multiple sites and surface diffusion between step and Ru(0001) terrace sites of varying ratios for nanoparticles of differing size revealed that dynamic strain yields catalytic ammonia synthesis conversion and turnover frequency comparable to industrial reactors (400°C, 200 atm) but at lower temperature (320°C) and an order of magnitude lower pressure (20 atm).

Modeling wave climates and wave energy attenuation in marsh terrace environments in the northern Gulf of Mexico

Marsh terracing is a coastal restoration technique that has been implemented in Louisiana and Texas for almost 30 years. Marsh terraces are segmented ridges of soil built in inland coastal ponds for the objectives of creating new marsh, disrupting fetch, and dissipating wind-driven wave energy, which causes marsh erosion. Despite widespread implementation, no numerical modeling studies have been conducted to understand the effect of terraces on wave climate in marsh environments. The objectives of this study were to: 1) simulate wave climates in marsh terrace fields using the Simulating WAves Nearshore (SWAN) model and evaluate the agreement between modeled and observed wave conditions and 2) assess the effectiveness of marsh terraces at reducing significant wave height by comparing wave climates in terraced sites with hypothetical unterraced sites. The SWAN model was used to simulate wind-waves at two terrace fields in coastal Louisiana. Model validation was performed using data collected with in situ wave instruments and wind data measured by NOAA stations located 25 km to the east and 62 km to the northeast of the study area. Results from this study modeled and measured small (0.03–0.14 m) and high–frequency waves (0.80–1.29 s) in the marsh terrace fields. Model validation revealed agreement between modeled and observed data, particularly for significant wave height and direction. Additionally, a comparison of wave climates in terraced and unterraced marsh environments indicated an average significant wave height reduction of 45% (min:18%, max: 84%) when terraces were present. Overall, the model was able to evaluate wave climates in marsh terrace fields and assess the effectiveness of this restoration technique in reducing significant wave height. The model's performance in this low energy and complex environment (shallow water, nonlinear shoreline, marsh fragmentated) is encouraging given the lack of research assessing wave parameters in marsh terrace environments.

A theoretical study of CO adsorption on Cu(211) surface with coverage effects.

CO adsorption on the Cu(211) surface was investigated using energy, geometry and vibrational data, which were produced through periodic DFT computations. Adsorption on the (111) terrace, as well as the previously reported top and bridge sites of the step-edges, was studied at 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00 monolayer (ML) CO coverage. Results showed that up to and including 0.50 ML, on-top or bridge adsorption is preferred on the step-edges. When 0.50 ML is exceeded, top-bridge alternating patterns become feasible on the step edges along with possible shifts towards the terrace. Several feasible patterns were identified at 0.66, 0.75, and 1.00 ML. Like step-edge adsorptions, alternating patterns on the terrace sites were found feasible at higher coverages. For all the studied cases, highest adsorption energies were found for the step-edge positions. In general, coordination number had a stronger effect than coverage on the calculated properties.

Gas phasevs.liquid phase: monitoring H2and CO adsorption phenomena on Pt/Al2O3by IR spectroscopy

The adsorption of H2and CO over Pt/Al2O3was studied in gas and in liquid phase by FT-IR and ATR-IR spectroscopies under otherwise similar conditions. The solvent competes with hydrogen and CO for terrace and kink metal sites.

High activity of step sites on Pd nanocatalysts in electrocatalytic dechlorination.

The role of step sites on nanocatalysts in the electrocatalytic dechlorination reaction (ECDR) was studied using 3 Pd nanocatalysts with different densities of step sites, which decreased in the order of: tetrahexahedral Pd{310} nanocrystals (THH Pd{310} NCs) > commercial Pd nanoparticles (Pd black) > cubic Pd{100} NCs. The two well-defined Pd NCs served as model catalysts and were prepared through the electrochemical square-wave potential (SWP) method. The toxic herbicide alachlor was first employed in this study as an objective probe to determine the dechlorination performance, which was quantified by the alachlor removal (Rala), the current efficiency (CEala), and the dechlorination selectivity (Sdes). The experimental results demonstrated that the THH Pd{310} NCs with abundant step sites exhibited much higher electrocatalytic performance compared to the cubic Pd{100} NCs with terrace sites. The combination of cyclic voltammetry studies, electrochemical in situ FTIR analysis, and density functional theory (DFT) calculations revealed that the adsorbed CO bond and generated on the step sites could lower the C-Cl bond splitting barrier, leading to a high ECDR efficiency. Other chlorinated organics with an activated carbon atom were also investigated, which revealed that the superiority of the step sites toward Cl-C bond breaking was particular to the compounds with CO bonds. This study provides a deep understanding of high actvitiy of step sites on Pd NCs in EHDC and a strategy to improve this important environmental electrocatalysis process.

Desorption trends of small alcohols and the disruption of intermolecular interactions at defect sites on Au(111).

Gold-based catalysts have received tremendous attention as supports and nanoparticles for heterogeneous catalysis, in part due to the ability of nanoscale Au to catalyze reactions at low temperatures in oxidative environments. Surface defects are known active sites for low temperature Au chemistry, so a full understanding of the interplay between intermolecular interactions and surface morphology is essential to an advanced understanding of catalytic behavior and efficiency. In a systematic study to better understand the adsorption and intermolecular behavior of small alcohols (C1-C4) on Au(111) defect sites, coverage studies of methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, and isobutanol have been conducted on Au(111) using ultrahigh vacuum temperature programmed desorption (UHV-TPD). These small alcohols molecularly adsorb on the Au(111) surface and high resolution experiments reveal distinct terrace, step edge, and kink adsorption features for each molecule. The hydrogen-bonded (H-bonded) networks of small alcohols on Au(111), except for 1-butanol and isobutanol, have been previously imaged on the molecular level at low temperatures by scanning tunneling microscopy. Primary C1-C3 alcohols exhibit planar H-bonded long extended zigzag chain networks while 2-butanol arranges in tetramer clusters of H-bonded molecules due to steric hindrance inhibiting the proximity of molecules on Au(111). Herein, the desorption energy of small primary alcohols was shown to trend linearly with increasing C1-C4 carbon chain length, indicating that the H-bonded molecular packing of 1-butanol resembles that of methanol, ethanol, and 1-propanol, while isobutanol and 2-butanol deviate from the trend. Butanol isomer studies allow the prediction of isobutanol long extended chains in contrast to tetramers. The distinction between the desorption of butanol isomers highlights the role of intermolecular interactions due to the difference in molecular packing structures on Au(111). Furthermore, by studying the energetics of terrace H-bonded networks in comparison with molecular adsorption at undercoordinated step edge and kink defect sites, it is shown that the contribution of stabilizing van der Waals forces to the overall adsorption energy is less for small alcohols adsorbed at kink sites (3.1 kJ mol-1 per CH2) and similar for those adsorbed at step edge (4.8 kJ mol-1 per CH2) and Au terrace sites (4.9 kJ mol-1 per CH2).

Further evidence in support of the recognition of the Freshwater Turtle Elseya oneiros (Testudines: Chelidae) from the Nicholson and Gregory Rivers of Northern Queensland

Thomson et al. (1997) proposed that the extant Elseya from the Nicholson-Gregory drainages in northwestern Queensland was conspecific with the holotype of Elseya lavarackorum, which comprised a fossil carapace and associated plastron excavated from the late Pleistocene Terrace Site at Riversleigh. Analysis of additional fossil material, and examination of a suite of 16 scute characters (eight for each of the carapace and plastron) by Joseph-Ouni et al. (2020) concluded that the two species were distinct and represented separate Elseya lineages and proposed the new name Elseya oneiros for the extant lineage. Recently, the Turtle Taxonomy Working Group (TTWG) in their 9th edition Checklist of Turtles of the World (TTWG 2021) questioned the status of E. oneiros and placed it in the synonymy of E. lavarackorum, making the claim, amongst others, that the skeletal characters of Thomson et al. (1997) were not addressed. Here we fully address the claims made and evaluate those skeletal characters. We also assess an additional nine thoracic skeletal characters of the pertinent Elseya species, including E. dentata sensu stricto. The results again do not support the conclusions of Thomson et al. (1997) of the holotype of Elseya lavarackorum being conspecific with the extant Elseya from the Nicholson-Gregory Rivers, reaffirms the proposal offered by Joseph-Ouni et al. (2020) for the placement of E. lavarackorum in the subgenus Elseya, and the status of E. oneiros in the Nicholson-Gregory drainages as a distinct species.

Structure-activity relationship of Pt catalyst on engineered ceria-alumina support for CO oxidation

In heterogeneous catalysis, the promotion of low temperature activity and enhancement of thermal stability simultaneously especially for precious metal catalysts is always highly demanded but very challenging. Herein we report a novel Pt catalyst on ceria-alumina (CeO2/Al2O3) support (Pt/CA-T) engineered by a two-step ceria deposition strategy, exhibiting superior thermal stability and low-temperature carbon monoxide (CO) oxidation activity after activation. Pt single sites anchored to engineered CeO2 edge sites are much more stable than that to CeO2 (111) surface, and such stable single sites can be transformed into highly active Pt clusters for efficient low-temperature CO oxidation. Active site identification indicates that the CO oxidation activity of different Pt sites follows such sequence: Pt cluster step sites ≈ Pt cluster terrace sites > Pt cluster corner sites ≫ Pt single sites on CeO2. The excellent low temperature activity of activated Pt/CA-T catalyst for CO oxidation is associated with its abundant Pt cluster step and terrace sites as well as rich Pt-CeO2 interfaces, which facilitate the adsorption of active CO species and superior oxygen activation/transfer ability. The present study provides new insights into the structure–activity relationship of Pt-CeO2-Al2O3 catalyst, which can also guide the preparation of other highly robust supported catalysts for important industrial applications.