Cerium Sites Research Articles

Regulating electron transfer between valence-variable cuprum and cerium sites within bimetallic metal–organic framework towards enhanced catalytic hydrogenation performance

Modulating the electron distribution between active sites in metal–organic frameworks (MOFs) offers a promising strategy for optimizing their catalytic performance. In this study, we employed a novel heterovalent substitution strategy to synthesize bimetallic organic frameworks (CuxCey-BTC) that feature dual active sites with copper (Cu) and cerium (Ce), Our objective was to achieve efficient hydrogenation of dicyclopentadiene (DCPD) by regulating the electron transfer between the valence-variable Cu and Ce species. The designed CuxCey-BTC were characterized using various spectroscopic and microscopic techniques, along with density functional theory (DFT) calculations, confirming the successful incorporation of bimetallic nodes within the framework structure and the electron transfer between them. The transfer of electrons from the less electronegative Ce to the Cu sites promotes the chemisorption of hydrogen gas (H2) on the electron-rich Cu sites, thereby optimizing the activation of the CC bond in DCPD. The Cu4Ce-BTC catalyst demonstrated exceptional performance, achieving complete conversion of DCPD and significantly surpassing monometallic MOFs. Moreover, we proposed a plausible pathway for the hydrogenation of DCPD. This work highlights the synergistic effects between bimetallic centers and offers a novel strategy to improve the MOFs’ catalytic activity by modulating electron distribution between dual active sites.

The Assembly of Cerium(III)-Containing Silicotungstate with Lewis Acid-Base Sites Enables the Selective C3-Alkenylation of Oxindole.

A cerium(III)-containing silicotungstate, [H2N(CH3)2]10NaK[KCe(SiW11O39)2(H2O)]·18.5H2O (CeSiW), was successfully synthesized and characterized. Structure analysis reveals that CeSiW is composed of two {SiW11O39} units connected by one cerium(III) cation to form a typical 1:2 sandwich structure, which is further expanding into a 1D chain linked by K+ ions. The oxygen-enriched surfaces of {SiW11O39} units and open cerium sites provide abundant Lewis base and acid sites in CeSiW. As a result, CeSiW efficiently catalyzed the C3-alkenylation of oxindoles with aldehydes through the simultaneous activation of both reaction substrates on its crystal framework. Various 3-benzylidene-oxindoles are synthesized with excellent yields and high E-selectivity under solvent-free conditions.

Operando Monitoring of Homolytic Cleavage of H2 into Surface Hydrides on Defective Cerium Dioxide Nanoparticles

AbstractThe use of ceria as catalyst in hydrogenation reactions is a recent trend, as they were uncovered to be active on a number of substrates, including alkynes, alkenes, and enones. While some studies focused on the use of well‐defined shapes, others emphasized the interest of defective structures. Overall, the meeting point of these studies is the need to characterize the surface reactivity vs. H2, by considering a number of interesting textures (films, nanopowders with various grain size or porosity), using monitoring techniques that preserve the original features of the materials. A key question is in particular to assess the possibility to form surface hydride through homolytic H2 splitting at cerium sites rather than at the oxygen one, a route recently highlighted as plausible. To address this question on small crystallites of CeO2, we designed a low‐temperature synthetic route for nanorods with an average grain size of 10 nm. Then, we employed near‐ambient‐pressure X‐ray photoelectron spectroscopy as an operando tool to monitor the cerium surface oxidation state during the initial annealing of the nanopowders, followed by exposure to a moderate pressure of H2 (0.52 mbar). We demonstrate that H2 homolytic splitting at cerium sites is the main activation process on this surface at 100 °C, leading to the oxidation of ca. 30 % of the surface cerium atoms from Ce3+ to Ce4+. The surface hydride species were however not stable at 250 °C, H2 was released, and cerium reduced back to Ce3+. A similar mechanism was observed on a defective ceria material obtained by calcination of CeO(OH)2, with comparable intensities. Overall, we report here CeO2 nanorods, exposing predominantly {100} and {110} facets, as showing an interesting surface reactivity for potential application in hydrogenation reactions, and we expose a straight operando methodology to delineate suitable temperatures to be used.

Atomically Dispersed Cerium Sites Immobilized on Vanadium Vacancies of Monolayer Nickel‐Vanadium Layered Double Hydroxide: Accelerating Water Splitting Kinetics

AbstractRational design of efficient single‐atom catalysts is a potential avenue to mitigate the sluggish oxygen evolution reaction (OER) kinetics. Adopting appropriate matrixes to stabilize the single‐atom active centers with the optimized geometric and electronic structure plays an essential role in enhancing catalytic activities. Herein, massive isolated Ce atoms are successfully anchored on monolayer nickel‐vanadium layered double hydroxide support (Ce SAs/m‐NiV LDH) via the vanadium defects trapping strategy, resulting in stabilized Ce single‐atom with the maximum loading of 8.07 wt.%. Benefitting from the strong synergetic electronic interaction between Ce single atoms and monolayer NiV LDH matrix, thus‐prepared catalyst possesses favorable OER (209 mV @ 10 mA cm−2) and water electrolysis performance (1.47 V @ 10 mA cm−2), surpassing other catalysts and even the commercial RuO2 catalyst. Density functional theory (DFT) calculations in combination with in situ electrochemical impedance spectroscopy analysis reveal that the immobilization of monatomic Ce can effectively narrow the band gap and strengthen the density states near the Fermi level as well as more easily adsorb the surficial OH–, leading to a lower charge transfer barrier and faster water splitting kinetics.

Unraveling the Electron Transfer Effect of Single-Metal Ce-N4 Sites via Mesopore-Coupling for Boosted Oxygen Reduction Activity.

The development of cerium (Ce) single-atom (SA) electrocatalysts for oxygen reduction reaction (ORR) with high active-site utilization and intrinsic activity has become popular recently but remains challenging. Inspired by an interesting phenomenon that pore-coupling with single-metal cerium sites can accelerate the electron transfer predicted by density functional theory calculations, here, a facile strategy is reported for directional design of a highly active and stable Ce SA catalyst (Ce SA/MC) by the coupling of single-metal Ce-N4 sites and mesopores in nanocarbon via pore-confinement-pyrolysis of Ce/phenanthroline complexes combined with controlling the formation of Ce oxides. This catalyst delivers a comparable ORR catalytic activity with a half-wave potential of 0.845V versus RHE to the Pt/C catalyst. Also, a Ce SA/MC-based zinc-air battery (ZAB) has exhibited a higher energy density (924Wh kgZn -1 ) and better long-term cycling durability than a Pt/C-based ZAB. This proposed strategy may open a door for designing efficient rare-earth metal catalysts with single-metal sites coupling with porous structures for next-generation energy devices.

Linear-scaling density functional theory (DFT) simulations of point, Frenkel and Schottky defects in CeO2

CeO2 (ceria) is a material of significant industrial and technological importance, used in solid oxide fuel cells and catalysis. Here, we explore the usage of linear-scaling density functional theory as implemented in the ONETEP code, which allows to use larger simulation cells. By using DFT+U calculations we revise the defect chemistry of ceria, including point defects, Frenkel and Schottky defects.We found that the ground state of an oxygen vacancy is associated to two neighbouring reduced cerium sites. A cerium vacancy is the least favourable point defect, where holes localise on neighbouring oxygen sites. It is more favourable to displace an oxygen interstitial defect away from the octahedral interstitial site, with the formation of a stable peroxide species. Our simulations show that a cerium interstitial is best accommodated in the octahedral interstitial site, as this minimises the distortion of the lattice.Placing a vacancy and an interstitial defect at a separation of 5.18 Å for the OF¡110¿ and 4.77 Å for the CeF¡111¿, stable Frenkel defects can be formed. We also studied the effect of different supercell size on the energetic ordering of Schottky defects, where the S¡111¿ is more favourable than the S¡110¿ for a given simulation cells containing 324 or more atoms.

Cerium-based metal–organic framework-conducting polymer nanocomposites for supercapacitors

Nanocomposites consisting of a cerium-based metal–organic framework (Ce-MOF-808) and a conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), are synthesized by performing the pulse electrodeposition of PEDOT within the Ce-MOF-808 thin films. Ratios between MOF and PEDOT in the composites are tunable by simply adjusting the charge density used for electropolymerization, and the crystallinity, morphology, and elemental distributions of the resulting nanocomposites are characterized. Electrochemical behaviors and capacitive performances of the pristine MOF, pristine PEDOT thin films, and composite thin films are investigated with the use of the neutral sodium sulfate aqueous electrolytes. The reversible electrochemical reactivity of the highly porous Ce-MOF-808 provides a pseudocapacitance, and the electronically conducting PEDOT can not only offer a remarkable double-layer capacitance but also facilitate the electronic conduction between the redox-active cerium sites present in the MOF. As a result, the composite can outperform both the pristine MOF and pristine electrodeposited PEDOT as the active materials for supercapacitors. Findings here suggest that the highly porous and redox-active cerium-based MOF thin films are capable to enhance the capacitive performances of the electrodeposited PEDOT thin films.

Constructing Heteroatom-Doped Transition-Metal Sulfide Heterostructures for Hydrogen Evolution Reaction

Transition-metal sulfide (TMS) has been regarded as the most promising alternative to construct non-noble metal catalysts in the electrochemical hydrogen evolution reaction (HER). The excellent edge activation of MoS2 and abundant catalytic active sites of Ce2S3 can be utilized as the premise of constructing heterogeneous materials for electrochemical applications. Afterward, the heteroatoms (C, N, O, and Na) have been introduced to increase the original number of active sites (the number of the S–Mo–S on the edge molecular layer of MoS2 and exposed metal active center of Ce2S3). Additionally, the heterostructure of HAs@MoS2/Ce2S3 and ordered/amorphous carbon can enhance the activity by creating defects and localized disorder fields and accelerating the charge separation/transfer from cerium (Ce) sites to molybdenum (Mo) sites. Combining the above advantages, HAs@MoS2/Ce2S3 shows promising properties toward HER not only in acidic environments with a low overpotential (147.0 mV) but also in alkaline (160.5 mV) environments.

Atomically dispersed cerium sites in carbon-doped boron nitride for photodriven CO2 reduction: Local polarization and mechanism insight

The rapid recombination of photogenerated electrons and holes on the bulk and surface of photocatalyst and the limited active sites seriously hinder the photocatalytic efficiency. Herein, we present a single-atom local coordination strategy to solve the above problems of C-BN photocatalysts. By introducing Ce atoms to form the Ce/B2N2 local structure, on the one hand, can effectively induce local polarization and form a local polarized electric field, which can promote the separation of photogenerated carriers. On the other hand, new Ce active sites are introduced and show a lower energy barrier for dissociation of the critical intermediate COOH*, while suppressing CH4 and H2 evolution in the competing reaction. The Ce/C-BN delivers a selective CO formation rate of 125.5 µmol g-1 h-1 in pure water and is one of the best photocatalysts in the system without additives. This work offers valuable guidance for the rational design of efficient photocatalysts.

Revealing active edge sites induced by oriented lattice bending of Co-CeO2 nanosheets for boosting auto-exhaust soot oxidation

Herein, a series of Cox-CeO2 nanosheet catalysts were elaborately synthesized by a one-step hydrothermal method. The CeO2 microsphere with crossed nanosheets can improve the soot-catalyst contact efficiency and the lattice substitution of Co ions for cerium sites in CeO2 results in the oriented lattice bending of Co-CeO2 nanosheets for improving adsorption/activation properties of NO and O2. Co2-CeO2 catalyst displays the highest H2O-tolerance activity (T50 = 334 °C, TOF = 1.32 h−1) and excellent stability during soot oxidation in the presence of H2O. Combined with characterizations and DFT calculations, the mechanism was proposed: the active edge sites located at the oriented lattice bending of Co-CeO2 nanosheets can activate surface oxygen and gaseous O2, and active oxygen species can boost NO oxidation to NO2, which is a crucial step of NOx-assistant catalytic mechanism for soot oxidation. It provides a promising way for the rational design of high-performance non-noble metal catalysts for soot oxidation in practical applications.

Enhanced redox properties of Gd-doped CeO2–TiO2 induced by oxygen vacancies and disordered structure

The redox properties of Gd-doped CeO2–TiO2 (xGd = 0.03, 0.09, and 0.15) was related to the oxygen defects and the local atomic structure. As the gadolinium doping concentration increased, a low-angle shift of the CeO2 (111) peak was observed. The EPR spectrum of the gadolinium-doped sample had an oxygen vacancy peak, indicating the oxygen vacancies induced by gadolinium. The O 1s core-level spectra showed that the ratio of oxygen vacancies gradually increased with the gadolinium doping concentration, and the Gd 4d and Ce 3d core-level spectra showed that Gd3+ reduced Ce4+ to Ce3+. An EXAFS analysis of the local atomic structures around Ce and Gd showed an increase in the Ce–O and Ce-(Ce,Gd) bond lengths and peak broadening occurred upon gadolinium doping, indicating bond disordering. The same Ce–O and Gd–O bond lengths suggested that the gadolinium was substituted for the cerium site. Surface chemisorption characterization was carried out by analyzing O2-TPD and H2-TPR profiles: the peaks for oxygen desorption and hydrogen reduction gradually shifted to lower temperatures as the dopant concentration increased. The quantities of desorbed oxygen and reduced hydrogen also increased. These enhanced redox properties resulted from disordered Ce3+-VO∙∙-Gd3+ acting as a surface active site, which promoted the redox reaction.

Atomically dispersed indium and cerium sites for selectively electroreduction of CO2 to formate

Atomically dispersed indium and cerium sites for selectively electroreduction of CO2 to formate

Single atomic cerium sites anchored on nitrogen-doped hollow carbon spheres for highly selective electroreduction of nitric oxide to ammonia

Electrocatalytic nitric oxide reduction reaction (NORR) at ambient environments not only offers a promising strategy to yield ammonia (NH3) but also degrades the NO contaminant; however, its application depends on searching for high-performance catalysts. Herein, we present single atomic Ce sites anchored on nitrogen-doped hollow carbon spheres that are capable of electro-catalyzing NO reduction to NH3 in an acidic solution, achieving a maximal Faradaic efficiency of 91 % and a yield rate of 1023 μg h−1 mgcat.−1 at –0.7 V vs RHE for NH3 formation, both of which outperform these on Ce nanoclusters and approach the best-reported results. Meanwhile, the single atomic Ce catalyst shows good structural and electrochemical stability during the 30-h NO electrolysis. Furthermore, when the single atomic Ce catalyst was used as cathodic material in a proof-of-concept of Zn–NO battery, it delivers a maximal power density of 3.4 mW cm−2 and a high NH3 yield rate of 309 μg h−1 mgcat.−1. Theoretical simulations suggest that the Ce-N4 active moiety can not only activate NO molecules via a strong electronic interaction but also reduce the free energy barrier of *NO transition to *NOH intermediate as the limiting step, and therefore boosting the NORR kinetics and suppressing the competitive hydrogen evolution.

Bragg diffraction by a magnetic all-in–all-out configuration with application to a cubic cerium pyrochlore oxide

The Bragg diffraction of neutrons and x rays are well suited to the task of determining the distribution of magnetization in crystals. Applications of the two techniques proceed by contrasting observed intensities with intensities calculated with a specific model, and changing the model as need be to achieve satisfactory agreement. An all-in--all-out (AIAO) magnetic configuration of magnetic dipoles on a cubic face-centered lattice with networks of corner-sharing tetrahedra is often mentioned in the context of pyrochlore oxides, for example, but the corresponding neutron and x-ray-diffraction patterns appear to not have been calculated. Our results for patterns of Bragg spots from an AIAO magnetic configuration defined by a magnetic space group are symmetry informed and yield exact reflection conditions. Specifically, a long-range order of magnetic dipoles is forbidden in our model. Bulk properties arise from higher-order multipoles that include quadrupoles and octupoles. Bragg spots that exclude all magnetic multipoles other than an octupole have been discovered, and they can be observed by both neutron diffraction and resonant x-ray diffraction. All magnetic multipoles allowed in diffraction by cerium ions $(4{f}^{1})$ are presented in terms of coefficients in a well-documented and unusual magnetic ground state. Symmetry of the cerium site in the cubic structure constrains the coefficients. Our scattering amplitudes have an application in both neutron- and x-ray diffraction experiments on ${\mathrm{Ce}}_{2}{\mathrm{Zr}}_{2}{\mathrm{O}}_{7}$, for example, and searches for the sought-after cerium octupole. Also presented for future use is a result for the total, energy-integrated magnetic neutron-scattering intensity by a powder sample.

Catalytic properties of Ce-MCM-41 prepared with ceric ammonium nitrate in the liquid-phase oxidation of benzyl alcohol

This work reports the influence of microstructural features in the catalytic performance, reaction kinetics and stability of a cerium-modified MCM-41 material prepared with ceric ammonium nitrate (Ce-MCM-CAN) in the liquid-phase oxidation of benzyl alcohol with tert-butyl hydroperoxide (TBHP) as oxidant. All the mentioned features were compiled and compared to other two Ce-MCM-41 catalysts prepared with CeCl3·7H2O and Ce(NO3)3·6H2O (Ce-MCM-Cl and Ce-MCM-NO3, respectively). Ce-MCM-CAN sample has offered a unique catalytic profile and considerable resistance towards conversion of isomorphous cerium sites in inactive agglomerated CeO2. In a typical catalytic essay at 80 °C and 24 h, Ce-MCM-CAN sample attains 54.6% of conversion, with 47.4 and 25.9% of benzaldehyde selectivity and yield, respectively. Nonetheless, kinetic essays demonstrates that the reaction continues after 24 h, mainly by reducing the aldehyde's selectivity and favoring the formation of benzoic acid, whereas Ce-MCM-Cl and Ce-MCM-NO3 samples has product formation stagnated after 20 h. After four catalytic cycles, the deactivation of Ce-MCM-CAN sample occurs mainly after the first cycle (reduction of 19.8% in conversion) with little influence in TBHP efficiency, while the other two model catalysts deactivate progressively after each cycle (reduction of 33.3 and 23.6% in conversion for Ce-MCM-Cl and Ce-MCM-NO3 samples, respectively) with loss of oxidant usage. Overall, the long-range ordering and pre-existing non-framework CeO2 nanoparticles in Ce-MCM-CAN sample is responsible for decreasing the deactivation rate. Such properties emerge from the counterbalanced synergy between chaotropic nitrate anions and condensation between [Ce(OH)4] species with silicate anions.

Quantum criticality in Ce1−xSmxCoIn5

Motivated by the possibility of observing the coexistence between magnetism and unconventional superconductivity in heavy-fermion ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{Sm}}_{x}\mathrm{Co}{\mathrm{In}}_{5}$ alloys, we studied how the samarium substitution on the cerium site affects the magnetic field-tuned-quantum criticality of stoichiometric $\mathrm{Ce}\mathrm{Co}{\mathrm{In}}_{5}$ by performing specific heat and resistivity measurements. By applying an external magnetic field, we have observed Fermi-liquid to non-Fermi-liquid crossovers in the temperature dependence of the electronic specific heat normalized by temperature and of the resistivity. We obtained the magnetic-field-induced quantum critical point (QCP) by extrapolating to zero temperature the temperature-magnetic field dependence at which the crossovers take place. Furthermore, a scaling analysis of the electronic specific heat is used to confirm the existence of the QCP. We have found that the magnitude of the magnetic-field-induced QCP decreases with increasing samarium concentration. Our analysis of heat capacity and resistivity data reveals a zero-field QCP for ${x}_{\text{cr}}\ensuremath{\approx}0.15$, which falls inside the region where Sm ions antiferromagnetism and superconductivity coexist.

Single Atomic Cerium Sites with a High Coordination Number for Efficient Oxygen Reduction in Proton-Exchange Membrane Fuel Cells

Fe–N–C electrocatalysts, as a representative of platinum group metal-free (PGM-free) catalysts, exhibit a comparable oxygen reduction reaction (ORR) activity but insufficient stability to that of commercial Pt/C in proton-exchange membrane fuel cells (PEMFCs), due to the unavoidable Fenton’s reactions. Herein, we report a hard-template approach to synthesize the rare-earth single-cerium-atom-doped metal–organic frameworks with a hierarchically macro–meso–microporous structure. Spherical aberration correction electron microscopy confirms the atomic dispersion of Ce sites. Additionally, X-ray absorption spectroscopy (XAS) was employed to further verify the coordination environment of Ce sites, which were stabilized by four-coordinated nitrogen atoms and six-oxygen atoms (Ce–N4/O6). The Ce sites were embedded in a hierarchically macro–meso–microporous N-doped carbon (Ce SAS/HPNC) catalyst, which exhibits a half-wave potential of 0.862 V in ORR and the highest power density of 0.525 W cm–2 under 2.0 bar H2/O2 in the fuel cell test.

Utilizing the Oxygen Carrier Property of Cerium Iron Oxide for the Low-Temperature Synthesis of 1,3-butadiene from 1-butene

Low-temperature oxidative dehydrogenation (ODH) of 1-butene to 1,3-butadiene is one of the challenging reactions in the polymer industry. Towards this a highly dispersed cerium iron oxide was synthesized by citrate gel combustion method and employed for the synthesis of 1,3-butadiene (BD) from 1-butene. The reaction was carried out at low temperature under an oxygen-free atmosphere in a continuous flow mode fixed bed reactor. A decrease in the lattice parameters observed from PXRD and high-resolution TEM analysis proved that iron occupies cerium sites in the crystal lattice. XPS, TPR, and oxygen uptake studies quantified the nature and abundance of different oxygen species. ODH was observed through consuming lattice oxygens. The vacancies generated could be filled by re-oxidation with an external supply of oxygen which will restore the catalytic activity demonstrating the Mars van Krevelen mechanism.

Effect of La3+, Pr3+, and Sm3+ triple-doping on structural, electrical, and thermal properties of ceria solid electrolytes for intermediate temperature solid oxide fuel cells

In the present study, we have investigated the effect of La3+, Pr3+, and Sm3+ triple-doping on structural, electrical, and thermal properties of ceria (Ce1–x(Lax/3Prx/3Smx/3)O2-δ). X-ray diffraction studies confirm the formation of samples with single-phase cubic-fluorite structure (JCPDS PDF File No: 34-0394). The lattice parameter values increases with increasing the dopant concentration (from 5.4190 Å to 5.4503 Å), shows that the dopants get totally dissolved into Cerium site. All the prepared samples were sintered at 1300 °C for 4 h. The values of relative densities were found to be higher than 95% and the high value is observed for the composition LPS8 i.e. 97.8%. The calculated crystalline size values were found to be in the range of 46 and 53 nm. Scanning electron microscope and energy dispersive spectroscopic techniques reveal the surface-microstructure and presence of elemental confirmation in the compositions. The average grain size values were found to be in between 231 and 366 nm. Raman spectroscopy study reveals the existence of oxygen vacancies in all the compositions and estimated concentration of oxygen vacancies is found to be high for LPS8 composition. The impedance spectroscopy revealed the total ionic conductivity and activation energies of all the compositions. The composition Ce0.76La0.08Pr0.08Sm0.08O2-δ (LPS8) displays the highest total ionic conductivity i.e. 0.043 S/cm with low activation energy i.e. 0.76 eV. Matched thermal expansion coefficient of the sample Ce0.76La0.08Pr0.08Sm0.08O2-δ with already existing electrode materials, makes it as an effective electrolyte material for the intermediate temperature–solid oxide fuel cell applications.

Nanosized palladium loaded on porous ceria: A three-dimensional boosted electrocatalyst for electrooxidation of C1 compounds

The solution combustion synthesis was used for preparation of porous CeO2 with two different fuels; glucose and citric acid, for combustion. The samples of porous CeO2 are labeled as PCOGlu and PCOCit. The surface area of PCOCit and PCOGlu were estimated as 44.50 ± 0.12, and 47.72 ± 0.16 m2 g−1, respectively. The cavities acidity, OH groups on surface, and its bond strength to the active cerium sites are compared by measuring the pH of zero charges; that it was 11.95 ± 0.02, and 11.90 ± 0.03 for PCOCit and PCOGlu, respectively. The nanosized palladium (NPd) was loaded on PCOGlu and PCOCitvia wetness incorporation. As-prepared nano-microstructure electrocatalysts are utilized in the electrooxidation of C1 compounds, including methanol, formaldehyde, and formic acid. The NPd-PCOGlu presents higher electrocatalytic activity, stability and CO-tolerance ability for the electrooxidation of C1 compounds as compared to the NPd-PCOCit and NPd as non-supported palladium; So that, the performance of the modified electrodes increase in the order of NPd < NPd-PCOCit < NPd-PCOGlu. The PCO with porous structural network affected on the electrochemical surface area, dispersion, and durability of NPd. It is effective the capability of removing the poisoning species of the electrooxidation of C1 compounds on NPd through the lattice oxygen, and the activation of an oxidation−reduction cycle between the high and low chemical valences of cerium, leading to improve the electrocatalytic efficiency of NPd. Lastly, the conversion of methanol to formaldehyde, and then to formic acid during electrooxidation is confirmed by using cyclic voltammetry.