Dispersion Of Pt Nanoparticles Research Articles

Hexanedioic acid mediated in situ functionalization of interconnected graphitic 3D carbon nanofibers as Pt support for trifunctional electrocatalysts

A unique approach of in situ functionalization has resulted in the uniform dispersion of Pt nanoparticles on the surface of hexanedioic acid modified electrospun 3D carbon nanofibers (ACNFs).

Correlation between electrochemical performance degradation and catalyst structural parameters on polymer electrolyte membrane fuel cell

AbstractThe catalysts performance degradation is a crucial issue in decay of the polymer electrolyte membrane fuel cell (PEMFC). The effect of Nafion content, dispersity of Pt nanoparticles and selected types of carbon support on the degradation of electrochemical surface area (ECSA) and double layer capacitance (DLC) were experimentally discussed by accelerated stress test (AST). The catalyst with 20wt% Nafion content exhibited better catalyst performance.i.e., the less DLC and ECSA degradation during AST. Catalysts with well Pt dispersity showed superior %ECSA (the percentage change of ECSA) retention. The heat-treated catalysts exhibited the lowest ECSA and DLC degradation rate due to the larger Pt particle and high carbon corrosion resistance. Moreover, a multi-order model describing the correlation between ECSA and DLC degradation was proposed, providing a vital reference for quantitatively investigating ECSA and DLC degradation in the catalysts with different catalysts structural parameters.

Spontaneous oxidation of arsenite on platinized TiO2 through activating molecular oxygen under ambient aqueous condition

The pre-oxidation of As(III) is essential for effective removal of arsenic in contaminated water. Although diverse arsenic oxidation methods have been developed, most require the input of chemical oxidants and external energy (e.g., electricity, photon energy). This study investigated the spontaneous catalytic oxidation of As(III) over Pt nanoparticles loaded on TiO2 under ambient aqueous conditions (i.e., air-saturated and room temperature). The proposed catalytic process requires dissolved O2 only as an oxidant, instead of chemical oxidants and energy input, where electrons spontaneously transfer from As(III) to O2 on the Pt–TiO2 catalyst. The oxidation rate of As(III) was highly dependent on (i) the content of Pt, (ii) the oxidation state of Pt, (iii) the presence of an electron acceptor (e.g., O2 and Fe(III)), (iv) the Pt support (e.g., TiO2, Al2O3, SiO2, etc.), and (v) the hetero-junction between Pt and TiO2. In this catalytic system, zero-valent Pt was confirmed as an active species for As(III) oxidation, and TiO2 acted as not only a support for the dispersion of Pt nanoparticles but also as an activator of in situ-generated H2O2 that is utilized in As(III) oxidation. Although Pt is expensive, the operation of Pt–TiO2 at room temperature without needing additional energy and chemical inputs, along with its high durability, can compensate for the high material cost. Therefore, the method presented here represents a viable treatment option for the pre-treatment of As(III)-contaminated water.

Small-sized Pt nanoparticles supported on hybrid structures of MoS2 nanoflowers/graphene nanosheets: Highly active composite catalyst toward efficient ethanol oxidation reaction studied by in situ electrochemical NMR spectroscopy

In this work, highly active MoS2 nanoflowers/graphene nanosheets (GNS) composites are successfully prepared through a simple hydrothermal method and are employed as Pt supports to prepare Pt/MoS2/GNS for ethanol oxidation. The catalyst is characterized both physically and electrochemically to investigate the effect of MoS2/GNS on Pt. Moreover, in situ electrochemistry - nuclear magnetic resonance, with the strength in structural characterization, quantitative analysis, and real-time measurement, is carried out to monitor molecular changes of reaction products and elucidate reaction mechanism of ethanol oxidation reaction, providing sampling resolution of 4s. Significantly, a small size of 5.4 nm Pt decorated Pt/MoS2/GNS is achieved. Pt/MoS2/GNS exhibits 2.1-fold increase in electrochemical active surface area, 2.2-fold increase in catalytic activity, and 2.0-fold increase in durability compared to commercial Pt/C during ethanol oxidation, which can be attributed to the synergistic effect of the interconnected nanoflower-on-nanosheet structure of MoS2/GNS, the better dispersion of Pt nanoparticles, and the interactions between substrate materials and Pt. The results suggest that Pt/MoS2/GNS could be an alternative electrocatalyst for efficient ethanol oxidation reaction. This work provides a promising strategy in the synthesis and monitoring of composite materials as high-performance ethanol oxidation catalysts.

Nitrogen-doped carbon black supported Pt–M (M = Pd, Fe, Ni) alloy catalysts for oxygen reduction reaction in proton exchange membrane fuel cell

Platinum (Pt) alloy catalysts on nitrogen doped carbon black was prepared and applied to a proton exchange membrane fuel cell, and the effects of nitrogen doping on the electrochemical properties were investigated. Pt was alloyed with 3d transition metals (Fe, Ni and Pd) in 3:1 atomic ratio and deposited onto nitrogen-doped carbon black (NCB). Alloying 3d transition metal causes an electron transfer from the Pt atom to the alloying element, depending on the work function and electronegativity of the element. The cell performances of Pt3Fe1 before and after N doping are almost the same due to the facilitation of electron transfer from Fe to Pt. It is attributed to the smallest work function of Fe, increasing the number of electron in the Pt 5d orbital. However, N doping for Pt–Pd and Pt–Ni alloys increases the total number of electrons per Pt atom, enhancing the oxygen reduction reaction (ORR) and the dispersion of Pt nanoparticles. The rotating disk electrode clearly shows an increase of onset potential upon nitrogen doping, suggesting the enhancement of the ORR. The accelerated durability test demonstrates the enhancement in durability and less agglomeration after 1200 cycles of operation upon nitrogen doping.

Preparation of Pt/(Ti3C2Tx)y-(MWCNTs)1-y electrocatalysts via a facile and scalable solvothermal strategy for high-efficiency methanol oxidation

Although direct methanol fuel cells are promising as “green” power generators for portable electronics, their further development has been largely hampered by the low-efficiency of the commercial anode catalysts. In this study, (Ti3C2Tx)y-(MWCNTs)1-y (0 ≤ y ≤1) supported Pt nanoparticle electrocatalysts were fabricated by a facile and scalable solvothermal strategy, after which two-dimensional(2D) Ti3C2Tx nanosheets were found to be intercalated and connected by conductive one-dimensional(1D) MWCNTs. Used for methanol oxidation reaction, the Pt/(Ti3C2Tx)0.5-(MWCNTs)0.5 catalyst exhibited the maximum electrochemical active surface area (ECSA, 154 m2/g) and excellent electrochemical activity (812.9 mA/mg), higher than not only Pt/Ti3C2Tx and Pt/MWCNTs of this study, but also many other related catalysts reported in literature. In addition, the CO-poisoning behavior was also alleviated using Pt/(Ti3C2Tx)0.5-(MWCNTs)0.5 instead of Pt/Ti3C2Tx and Pt/MWCNTs. Such a superior performance can be attributed to the well dispersion of Pt nanoparticles (∼3.8 nm), enhanced layer distance of Ti3C2Tx to capture more Pt nanoparticles, and conductive action of MWCNTs to connect Ti3C2Tx. This study opens a new perspective for developing high performance supercapacitors using Pt catalysts supported by 1D-intercalated 2D materials.

Facile Synthesis of Nanoporous Pt‐Encapsulated Ir Black as a Bifunctional Oxygen Catalyst via Modified Polyol Process at Room Temperature

AbstractThe exploitation of a bifunctional oxygen catalyst with high efficiency is crucial for a high‐performance unitized regenerative fuel cell (URFC). However, the existing bifunctional oxygen catalysts still suffer from low catalytic efficiency due to sluggish oxygen electrode reactions toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, we report on a facile synthesis of nanoporous Pt‐encapsulated Ir black with Pt/Ir mass ratio of 55/45 (Pt55@Ir45) via a newly modified polyol process at room temperature with the aid of water. The resulting Pt55@Ir45 catalyst demonstrated to be highly efficient and robust for both ORR and OER, relative to a mixture of commercial Pt and Ir black with Pt/Ir mass ratio of 50/50 (Pt50/Ir50). Mass activity of Pt55@Ir45 presented an 8.7‐ and 1.6‐fold increase toward ORR and OER, respectively, compared with the Pt50/Ir50 catalyst. The enhanced bifunctional performance was rationalized in terms of the maximized Pt utilization, achieved by the excellent dispersion of Pt nanoparticles, and the nanoporous Pt layer constructing a conductive network without impeding the transport of oxygen and water molecules. Our work demonstrates an effective means to encapsulate nanoporous Pt layers on Ir black for the fabrication of bifunctional oxygen catalysts.

Platinum supported cellulose-based carbon with oxygen-containing functional groups for benzyl alcohol oxidation

Porous carbon was prepared through a simple and efficient method using microcrystalline cellulose as carbon source. Compared with pristine carbon (C-1), nitric acid treated carbon (C-2) has more acidic oxygen-containing groups on its surface (acid density: 0.14 mmol/g for C-1 and 2.13 mmol/g for C-2). Pt supported Pt/C-2 behaves a substantially enhanced catalytic oxidation activity of benzyl alcohol (conversion of 71.7%) compared with Pt/C-1(conversion of 37.2%) under the same conditions. Further characterizations and experiments indicate that the excellent dispersion of Pt nanoparticles and strong hydrogen bonding interaction between benzyl alcohol and Pt/C-2 are crucial for the enhanced catalytic activity. Our experimental results also show that mild temperature (60 °C) and non-polar solvents are more beneficial for the reaction, and O2 atmosphere is a necessity for benzyl alcohol oxidation.

MoS2-rGO hybrid architecture as durable support for cathode catalyst in proton exchange membrane fuel cells

Carbon black is utilized as a conventional electrocatalyst support material for proton exchange membrane fuel cells. However, this support is prone to corrosion under oxidative and harsh environments, thus limiting the durability of the fuel cells. Meanwhile, carbon corrosion would also weaken the linkage between Pt and the support material, which causes Pt agglomeration, and consequently, deterioration of the cell performance. To overcome the drawbacks of a Pt/C electrocatalyst, a hybrid support material comprising molybdenum disulfide and reduced graphene oxide is proposed and synthesized in this study to exploit the graphitic nature of graphene and the availability of the exposed edges of MoS2. TEM results show the uniform dispersion of Pt nanoparticles over the MoS2-rGO surface. Electrochemical measurements indicate higher ECSA retention and better ORR activity after 10000 potential cycles for Pt/MoS2-rGO as compared to Pt/C, demonstrating the improved durability for this hybrid support material.

Remarkably enhanced activity of 4A zeolite modified Pt/reduced graphene oxide electrocatalyst towards methanol electrooxidation in alkaline medium

A novel 4A zeolite modified platinum/reduced graphene oxide (Pt/RGO-4A zeolite) electrocatalyst has been successfully synthesized by one-step chemical co-reduction method. The electrocatalytic performances of Pt/RGO-4A zeolite electrocatalyst for methanol electrooxidation are investigated in 1.0 M CH3OH containing 1.0 M KOH solution. The results demonstrate that, with loading of 10% of 4A zeolite, Pt/RGO-4A zeolite electrocatalyst shows higher current density of 319.40 mA mg−1 than Pt/RGO electrocatalyst (88.64 mA mg−1) at the potential of 0.70 V. In addition, Pt/RGO-4A zeolite electrocatalyst still exhibits high electrocatalytic activity even after 4000-s operation, suggesting satisfactory long-term durability. The remarkably enhanced electrocatalytic performances are attributed to the nanoporous structure of 4A zeolite, which significantly promotes the dispersion of Pt nanoparticles and provides substantial fast flow paths for reactants. The results suggest a potential application of Pt/RGO-4A zeolite electrocatalyst to methanol electrooxidation.

Role of hierarchical micro-mesoporous structure of ZSM-5 derived from an embedded nanocarbon cluster synthesis approach in isomerization of alkenes, catalytic cracking and hydrocracking of alkanes

Hierarchical micro-mesoporous ZSM-5 zeolites synthesized via an embedded nanocarbon cluster approach were studied for isomerization of n-butene, catalytic cracking of n-hexane, catalytic cracking and hydrocracking of n-hexadecane. The introduction of mesoporosity into ZSM-5 zeolite framework was achieved by using carbon/SiO2 composite obtained from a carbonaceous gas deposition on silica gel as a mesoporogen. The synthesized hierarchical ZSM-5 zeolites with different Si/Al ratios were characterized by means of XRD, ICP-OES, N2 adsorption-desorption isotherm measurement, TEM, 27Al MAS NMR, NH3-TPD, FTIR of pyridine adsorption and constraint index (CI) test. Compared with the conventional H-ZSM-5, the hierarchical H-ZSM-5 exhibits an enhancement in the catalytic activity in terms of higher reactant conversion and product yield for isomerization of n-butene and catalytic cracking of n-hexadecane, as the mesopores provide larger pores as well as improved accessible active sites. Moreover, Pt loaded on hierarchical H-ZSM-5 exhibit a remarkably enhanced catalytic activity in hydrocracking of n-hexadecane compared to Pt loaded on conventional H-ZSM-5 due to a smaller and higher dispersion of Pt nanoparticles. For n-hexane cracking, the presence of mesopores does not improve n-hexane conversion on the fresh catalyst because this reaction proceeds via monomolecular pathway and the corresponding reaction species are smaller than 10-ring pore windows of ZSM-5 zeolite. However, the hierarchical structure improves the catalytic stability in n-hexane cracking due to the presence of mesopores, which can shorten the diffusion path length, suppressing the consecutive reactions and, thus reducing the coke formation.

Costus speciosus leaf extract assisted CS-Pt-TiO2 composites: Synthesis, characterization and their bio and photocatalytic applications

The antioxidative and antidiabetic properties of Costus speciosus leaf extract assisted nanoparticles (CS–Pt modified TiO2) were compared with pristine TiO2 NPs along with standard ascorbic acid (AA). CS-Pt nanoparticles were synthesized through bioreduction process and supported on titanium dioxide semiconductor. Costus speciosus (CS) leaf extract was used as reducing and capping agent. Initially, CS-Pt nanoparticles synthesis was carried out with ethanolic extract of CS, later, two different wt% of CS-Pt supported TiO2 were prepared through sol-gel cum solvothermal process. The prepared materials have been characterized using different characterization techniques such as XRD, FT-IR, Raman, SEM, HR-TEM, EDS, DRS, PL and XPS measurements. CS-Pt-TiO2 nanocomposites showed well dispersion of Pt nanoparticles on TiO2 surface. The prepared materials have been effectively utilized for in-vitro antioxidant and in vitro antidiabetic activity. Moreover, the photocatlytic activity of the materials has been tested toward NBB degradation under visible light. CS-Pt NPs modified TiO2 composites show better activity when compared with pristine TiO2 in all cases.

(Invited) Polymer Hydrogel-Derived Carbon Supports for Highly Stable Pt/C Cathode Catalysts in PEM Fuel Cells

Conventional carbon supports used in current Pt/C fuel cell catalysts are not electrochemically stable at high potentials (up to 1.5 V) with weak interaction with Pt nanoparticles, therefore leading to poor catalyst durability in proton exchange membrane fuel cells (PEMFCs). Increasing the degree of graphitization improves corrosion resistance seems an effective solution, but it often leads to low surface area and insufficient porosity, and poor Pt nanoparticle dispersion on the support. Here, we represent a new type of highly graphitized and porous carbon for Pt catalysts, showing significantly enhanced stability and high oxygen reduction reaction (ORR) performance in acidic media for PEMFCs. The approach uses an inexpensive polymer hydrogel precursor in combination with transition metals such as Fe, Co, Ni, Cu, or/and Mn, which followed by multiple annealing treatments. The 3D hydrogel provides high porosity at multiple scales while transition metals catalyzes the graphitization process. The resulting porous morphology helps to improve the dispersion and utilization of Pt nanoparticles. Among studied metals, Mn plays a critical role in improving the corrosion resistance by increasing the degree of graphitization. Compared to commercial Pt/C catalysts based on XC-72 carbon black support, the hydrogel based Pt/C catalyst exhibits remarkably enhanced stability and decreased carbon corrosion rates in accelerated stress tests (ASTs) in both aqueous electrolyte and membrane electrode assemblies (MEAs) via potential or voltage cycling from 1.0 to 1.5 V. The new Pt/C catalyst show excellent dispersion of Pt nanoparticles before and after durability testing, which may be attributed to strengthened interactions between carbon supports and Pt nanoparticles as well as the significantly mitigated corrosion rates of carbon. The highly stable new carbon supports provide a very promising solution to address the durability issue of PEMFCs partially caused by current cathode Pt/C catalysts.

Platinum/Nickel Bicarbonate Heterostructures towards Accelerated Hydrogen Evolution under Alkaline Conditions.

Heterostructured nanomaterials, generally have physicochemical properties that differ from those of the individual components, and thus have potential in a wide range of applications. New platinum (Pt)/nickel bicarbonate (Ni(HCO3 )2 ) heterostructures are designed for an efficient alkaline hydrogen evolution reaction (HER). Notably, the specific and mass activity of Pt in Pt/Ni(HCO3 )2 are substantially improved compared to the bare Pt nanoparticles (NPs). The Ni(HCO3 )2 provides abundant water adsorption/dissociation sites and modulate the electronic structure of Pt, which determine the elementary reaction kinetics of alkaline HER. The Ni(HCO3 )2 nanoplates offer a platform for the uniform dispersion of Pt NPs, ensuring the maximum exposure of active sites. The results demonstrate that, Ni(HCO3 )2 is an effective catalyst promoter for alkaline HER.

Platinum/Nickel Bicarbonate Heterostructures towards Accelerated Hydrogen Evolution under Alkaline Conditions

AbstractHeterostructured nanomaterials, generally have physicochemical properties that differ from those of the individual components, and thus have potential in a wide range of applications. New platinum (Pt)/nickel bicarbonate (Ni(HCO3)2) heterostructures are designed for an efficient alkaline hydrogen evolution reaction (HER). Notably, the specific and mass activity of Pt in Pt/Ni(HCO3)2 are substantially improved compared to the bare Pt nanoparticles (NPs). The Ni(HCO3)2 provides abundant water adsorption/dissociation sites and modulate the electronic structure of Pt, which determine the elementary reaction kinetics of alkaline HER. The Ni(HCO3)2 nanoplates offer a platform for the uniform dispersion of Pt NPs, ensuring the maximum exposure of active sites. The results demonstrate that, Ni(HCO3)2 is an effective catalyst promoter for alkaline HER.

Increased interface effects of Pt[sbnd]Fe alloy/CeO2/C with Pt[sbnd]Fe selective loading on CeO2 for superior performance in direct methanol fuel cell

Here, a simple two-step solvothermal approach has been employed to synthesize PtFe alloy (or Pt)/CeO2/C with PtFe (or Pt) selective loading on CeO2 nanoparticles. In addition, the selective loading of PtFe alloy or Pt nanoparticles on the surface of CeO2 is achieved under weak alkaline environment, which is mainly attributed to the opposite electrostatic force between H+ enriched on the surface of CeO2 particles and OH− covered with carbon supporters. As-prepared PtFe alloy (or Pt)/CeO2/C catalysts with two-stage loading structures show more excellent electro-catalytic efficiency for methanol oxidation as well as duration compared with commercial Pt/C and PtCeO2/C with random loading structure. Further, single-cell assembly based on Pt3Fe/CeO2/C as the anode catalyst exhibits a maximum power density of 31.1 mW cm−2, which is 1.95 times that of an analogous cell based on the commercial Pt/C. These improved performances with considerable low Pt content (<0.3 mg cm−2) are mainly ascribed to the abundant three phase interfaces (PtCeO2 carbon) induced by the selective and efficient dispersion of Pt nanoparticles on ceria.

Dual role of hemin in Pt nanoparticle deposition on carbon nanotubes for methanol electro-oxidation and oxygen reduction

This paper presents a novel and simple non-covalent method to synthesize a double-cladding coaxial structured hybrid by depositing Pt nanoparticles on hemin-coated multi-walled carbon nanotubes (MWCNTs). The Pt nanoparticles cooperated with hemin can be used for methanol electro-oxidation and oxygen reduction. Transmission electron microscopy showed that the Pt nanoparticles were uniformly dispersed on the hemin-coated MWCNTs with a small particle size and a narrow particle size distribution. Cyclic voltammetry tests revealed that the as-prepared Pt/hemin-coated MWCNT electrocatalysts exhibited higher electrochemical surface area (67.46 m2/g) and current density (425.0 mA mg−1) for methanol oxidation than Pt/MWCNTs. These improvements can be attributed to the dual role of hemin in the dispersion of Pt nanoparticles on functionalized MWCNTs and the synergy of catalysis in methanol electro-oxidation and oxygen reduction. It's the first time to report the functionalization of CNTs with catalytic hemin as the binder between CNTs and the metal nanoparticles of MOR or ORR catalyst.

0.7 wt% Pt/beta-Al2O3 as a highly efficient catalyst for the hydrodeoxygenation of FAMEs to diesel-range alkanes

Four kinds of hydrodeoxygenation catalysts with various beta zeolite contents, Pt/Al2O3, Pt/beta(20%)-Al2O3, Pt/beta(50%)-Al2O3 and Pt/beta(80%)-Al2O3, were prepared by the wet-impregnation method and characterized by powder XRD, BET, NH3-TPD, TEM, STEM and EDX techniques. The prepared catalysts were used for the efficient production of biodiesel-range alkanes. The proportion of beta zeolite significantly affected the hydrodeoxygenation activity of catalysts. The highest FAMEs conversion rates (99.5%) and C15–C18 alkane yields (84.7%) were obtained by the Pt/beta(20%)-Al2O3 catalyst due to its larger mesoporous pore volume, moderate acidity and high dispersion of Pt nanoparticles. After compiling the product distribution results, a reaction pathway for the hydrodeoxygenation of FAMEs was discussed.

Novel nanorod Ti0·7Ir0·3O2 prepared by facile hydrothermal process: A promising non-carbon support for Pt in PEMFCs

Late transition metal doped TiO2 has been exploited for generating efficient catalyst support by enhancing electrical conductivity and modifying properties of TiO2. The Ti0·7Ir0·3O2 nanorod (NRs), a novel catalyst support for Pt nanoparticles, was prepared for the first time via single-step hydrothermal process at low temperature using IrCl3·3H2O and TiCl4 as starting materials. We found that the Ti0·7Ir0·3O2 NRs with 70–80 nm in length and 25–30 nm in width is successful prepared at 210 °C for 12 h without utilizing surfactants or stabilizers. In addition, the Ti0·7Ir0·3O2 NRs was presented principally as a single-phase solid with the TiO2 is in the rutile form with high crystallinity without using further treatment after synthesis. More importantly, we found that the Ti0·7Ir0·3O2 NRs possesses high electrical conductivity (0.028 S cm−1) dealing the intrinsically non-conducted drawback of TiO2. The Pt nanoparticles were then deposited on the support of Ti0·7Ir0·3O2 NRs via chemical reduction method. The properties of 20 wt % Pt/Ti0·7Ir0·3O2 NRs electrocatalyst were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), the cyclic voltammetry (CV). The uniformly distributed small Pt nanoparticles (3–4 nm diameter) were well adhered to the Ti0·7Ir0·3O2 NRs. The electrochemically active surface area (ECSA) of 20 wt % Pt/Ti0·7Ir0·3O2 NRs was higher than that of the commercial 20 wt % Pt/C (E-TEK) due to the small size and good dispersion of Pt nanoparticles on the surface of Ti0·7Ir0·3O2 NRs. Moreover, the ECSA value of the Pt/Ti0·7Ir0·3O2 NRs retained up to 88% after 2000 cycles of cyclic voltammetry, suggesting the high stability of catalyst resulted from strong metal support interaction (SMSI) of Titania-based materials with the noble metals. More importantly, the onset potential of Pt/Ti0·7Ir0·3O2 NRs catalyst towards oxygen reduction reaction is more positive (∼80 mV) compared to commercial Pt/C, indicating the high catalytic activity of the Pt/Ti0·7Ir0·3O2 NRs catalyst. The results of this research suggested that novel Ti0·7Ir0·3O2 NRs could be applied as promising robust non-carbon support for Pt. This research also creates a preliminary step for investigating systematically promising Iridium doped Titania materials.

Pt/C@MnO2 composite hierarchical hollow microspheres for catalytic formaldehyde decomposition at room temperature

Hierarchical carbon@manganese oxide (MnO2) core-shell heterostructure was fabricated by a facile hydrothermal method with hollow carbon spheres as a sacrificial template, and then deposited with platinum (Pt) nanoparticles (NPs). The as-prepared Pt/C@MnO2 composite catalyst exhibited superb performance for removing formaldehyde (HCHO) at room temperature compared with the Pt loaded on MnO2 microspheres or commercial MnO2. The MnO2 nanosheet-assembled hierarchical architecture endowed Pt/C@MnO2 with larger specific surface area and open porous structure, which not only promotes the high dispersity of Pt NPs but also facilitates the diffusion and adsorption of HCHO onto the catalyst surface. The abundant surface active oxygen species resulted from the activation and dissociation of O2 adsorbed at oxygen vacancies adjacent to Pt NPs, and were identified as the primary active species for converting HCHO into intermediates such as dioxymethylene, formate and carbon monoxide. This work might provide enlightenment for designing morphology-dependent and highly active catalysts for HCHO elimination at ambient temperature.