Pt In Catalysts Research Articles

Phase Transfer Catalysis: New Technology to Boost Organic Farming

Introduction of Phase Transfer Catalysis (PTC) technology, which was developed in the 1970s has revolutionised the dyes and pharmaceutical industries in many ways. PTC is a process that facilitates the organic compounds to move from one phase to another phase, without any change in the chemical qualities. Application of this technology was explored in the 1980s for agriculture, by using different plant extracts as PT catalysts. The objective was to facilitate increased absorption of nutrients by plants, by stimulating plant growth and easy availability of nutrients in the soil. Introduction of nano-carbon materials with nutrients and herbal growth stimulants could further support the crop growth by facilitating increased uptake of nutrients, apart from enabling the plants to develop resilience to harsh environmental conditions, resulting in higher crop yields. Some organic bio-stimulants developed recently by Snehasrusthi Group in India have been very successful in improving the growth, yield and quality of several seasonal and perennial crops in India. These bio-stimulants have excellent potential to boost organic agricultural production and income of farmers in the future.

Boosting the Stability of Subnanometer Pt Catalysts by the Presence of Framework Indium(III) Sites in Zeolite.

Subnanometer metal clusters show advantages over conventional metal nanoparticles in numerous catalytic reactions owing to their high percentage of exposed surface sites, abundance of under-coordinated metal sites and unique electronic structures. However, the applications of subnanometer metal clusters in high-temperature catalytic reactions (>600 °C) are still hindered, because of their low stability under harsh reaction conditions. In this work, we have developed a zeolite-confined bimetallic PtIn catalyst with exceptionally high stability against sintering. A combination of experimental and theoretical studies shows that the isolated framework In(III) species serve as the anchoring sites for Pt species, precluding the migration and sintering of Pt species in the oxidative atmosphere at ≥650 °C. The catalyst comprising subnanometer PtIn clusters exhibits long-term stability of >1000 h during a cyclic reaction-regeneration test for ethane dehydrogenation reaction.

Boosting the Stability of Subnanometer Pt Catalysts by the Presence of Framework Indium(III) Sites in Zeolite

AbstractSubnanometer metal clusters show advantages over conventional metal nanoparticles in numerous catalytic reactions owing to their high percentage of exposed surface sites, abundance of under‐coordinated metal sites and unique electronic structures. However, the applications of subnanometer metal clusters in high‐temperature catalytic reactions (>600 °C) are still hindered, because of their low stability under harsh reaction conditions. In this work, we have developed a zeolite‐confined bimetallic PtIn catalyst with exceptionally high stability against sintering. A combination of experimental and theoretical studies shows that the isolated framework In(III) species serve as the anchoring sites for Pt species, precluding the migration and sintering of Pt species in the oxidative atmosphere at ≥650 °C. The catalyst comprising subnanometer PtIn clusters exhibits long‐term stability of >1000 h during a cyclic reaction‐regeneration test for ethane dehydrogenation reaction.

A General Descriptor for Single‐Atom Catalysts with Axial Ligands

AbstractDecoration of an axial coordination ligand (ACL) on the active metal site is a highly effective and versatile strategy to tune activity of single‐atom catalysts (SACs). However, the regulation mechanism of ACLs on SACs is still incompletely known. Herein, we investigate diversified combinations of ACL‐SACs, including all 3d–5d transition metals and ten prototype ACLs. We identify that ACLs can weaken the adsorption capability of the metal atom (M) by raising the bonding energy levels of the M−O bond while enhancing dispersity of the d orbital of M. Through examination of various local configurations and intrinsic parameters of ACL‐SACs, a general structure descriptor σ is constructed to quantify the structure–activity relationship of ACL‐SACs which solely based on a few key intrinsic features. Importantly, we also identified the axial ligand descriptor σACL, as a part of σ, which can serve as a potential descriptor to determine the rate‐limiting steps (RLS) of ACL‐SACs in experiment. And we predicted several ACL‐SACs, namely, CrN4‐, FeN4‐, CoN4‐, RuN4‐, RhN4‐, OsN4‐, IrN4‐ and PtN4‐ACLs, that entail markedly higher activities than the benchmark catalysts of Pt and IrO2 for oxygen reduction reaction and oxygen evolution reaction, respectively, thereby supporting that the general descriptor σ can provide a simple and cost‐effective method to assess efficient electrocatalysts.

A General Descriptor for Single-Atom Catalysts with Axial Ligands.

Decoration of an axial coordination ligand (ACL) on the active metal site is a highly effective and versatile strategy to tune activity of single-atom catalysts (SACs). However, the regulation mechanism of ACLs on SACs is still incompletely known. Herein, we investigate diversified combinations of ACL-SACs, including all 3d-5d transition metals and ten prototype ACLs. We identify that ACLs can weaken the adsorption capability of the metal atom (M) by raising the bonding energy levels of the M-O bond while enhancing dispersity of the d orbital of M. Through examination of various local configurations and intrinsic parameters of ACL-SACs, a general structure descriptor σ is constructed to quantify the structure-activity relationship of ACL-SACs which solely based on a few key intrinsic features. Importantly, we also identified the axial ligand descriptor σACL, as a part of σ, which can serve as a potential descriptor to determine the rate-limiting steps (RLS) of ACL-SACs in experiment. And we predicted several ACL-SACs, namely, CrN4-, FeN4-, CoN4-, RuN4-, RhN4-, OsN4-, IrN4- and PtN4-ACLs, that entail markedly higher activities than the benchmark catalysts of Pt and IrO2 for oxygen reduction reaction and oxygen evolution reaction, respectively, thereby supporting that the general descriptor σ can provide a simple and cost-effective method to assess efficient electrocatalysts.

Enhanced PtIn Catalyst via Ce-Assisted Confinement Effect in Propane Dehydrogenation

Enhanced PtIn Catalyst via Ce-Assisted Confinement Effect in Propane Dehydrogenation

Mg-MOF-74 Derived Defective Framework for Hydrogen Storage at Above-Ambient Temperature Assisted by Pt Catalyst.

Metal-organic frameworks (MOFs) are promising candidates for room-temperature hydrogen storage materials after modification, thanks to their ability to chemisorb hydrogen. However, the hydrogen adsorption strength of these modified MOFs remains insufficient to meet the capacity and safety requirements of hydrogen storage systems. To address this challenge, a highly defective framework material known as de-MgMOF is prepared by gently annealing Mg-MOF-74. This material retains some of the crystal properties of the original Mg-MOF-74 and exhibits exceptional hydrogen storage capacity at above-ambient temperatures. The MgO5 knots around linker vacancies in de-MgMOF can adsorb a significant amount of dissociated and nondissociated hydrogen, with adsorption enthalpies ranging from -22.7 to -43.6kJmol-1, indicating a strong chemisorption interaction. By leveraging a spillover catalyst of Pt, the material achieves a reversible hydrogen storage capacity of 2.55wt.% at 160°C and 81bar. Additionally, this material offers rapid hydrogen uptake/release, stable cycling, and convenient storage capabilities. A comprehensive techno-economic analysis demonstrates that this material outperforms many other hydrogen storage materials at the system level for on-board applications.

An efficient cathode electrocatalyst for anion exchange membrane water electrolyzer

A high performance and durable electrocatalyst for the cathodic hydrogen evolution reaction (HER) in anion exchange membrane (AEM) water electrolyzers is crucial for the emerging hydrogen economy. Herein, we synthesized Pt–C core-shell nanoparticles (core: Pt nanoparticles, shell: N-containing carbon) were uniformly coated on hierarchical MoS2/GNF using pyrolysis of h-MoS2/GNF with a Pt-aniline complex. The synthesized Pt–C core-shell@h-MoS2/GNF (with 11.3 % Pt loading) showed HER activity with a lower overpotential of 30 mV at 10 mA cm−2 as compared to the benchmark catalyst 20 % Pt–C (41 mV at 10 mA cm−2) with improved durability over 94 h at 10 mA cm−2. Furthermore, we investigated the structural stability and hydrogen adsorption energy for Pt13 cluster, C90 molecule, h-MoS2 sheet, Pt13–C90 core-shell, and Pt13–C90 core-shell deposited h-MoS2 sheets using density functional theory (DFT) simulations. We investigated the Pt–C core-shell@h-MoS2/GNF catalyst active sites during HER performance using in-situ Raman analysis as well as DFT. We fabricated AEM water electrolyzers with cathode catalysts of Pt–C core-shell@h-MoS2/GNF and evaluated device performance with 0.1 and 1.0 M KOH at 20 and 60 °C. Our work provides a new pathway to design core-shell electrocatalysts for use in AEM water electrolyzers to generate hydrogen.

Methanol Sensing Behavior Analysis of Pt-Sn/C Based Micro DMFC

A MEMS-based micro DMFC structure of 1cm2, fabricated using 3D printing technology. Pt-Sn/C is offering good power density which was identified as the novel catalyst in DMFC. The synthesized nanoparticles of Pt-Sn/C was characterized and the MEA of the same was fabricated with Nafion membrane was and the cathode catalyst of pure Pt. Physically attached MEA with the DMFC cell was tested for the methanol of different concentrations and different operating temperature of the cell. The polarization curves were plotted for the redox reaction. The performance of the cell was increased with the increment of the temperature. At the same time, the considerable amount of current was observed while the cell was operated at low temperature The produced current was amplified and the sensor’s minimal detection ability of methanol was tested and results are presented.

In-situ constructed ultrathin hydrotalcite derivative supported PtIn catalyst for isobutane direct dehydrogenation

The stable and ultrathin hydrotalcite nanosheets with thickness of ca. 1.0 nm have been built on the surface of Al2O3 by sharing Al element and using layer growth inhibitor formamide. Based on the topological transformation characteristics of hydrotalcite and the structural memory effect of calcined product, the supported PtIn bimetallic catalyst was achieved by stepwise incipient wetness impregnation method followed by calcination and reduction, and evaluated in isobutane direct dehydrogenation (IDH) to isobutene. The derived ultrathin bimetallic catalyst possesses excellent IDH activity under extreme conditions, in which the isobutane conversion and isobutene selectivity can remain above 63% and 92% respectively, and the turnover frequency is as high as 13.45 s−1. The excellent activity can be attributed to the formation of ultrathin hydrotalcite precursor, which can greatly enhance the specific surface area, interaction among metal components, surface acidity of weak- and medium-acid sites and surface In3+/In0 ratio, and further effectively inhibit carbon deposition and improve dispersion and stability of active Pt species in the corresponding derivative.

Cyclic ether on Pt-based carbon support for enhanced alkaline hydrogen evolution

Oxygen functionalization of carbon support has widely been explored for improving the catalytic performance of carbon-supported Pt catalysts (Pt/C) since the existential state of Pt is significantly affected by the surface properties of the carbon support. However, the impact of oxygen functionalization of carbon surface on the catalytic performances of Pt/C catalysts for alkaline hydrogen evolution reaction (HER) has not yet been adequately investigated. Herein, graphite (GP) was used as model support and oxidized through nitric acid to introduce enriched hydroxyl groups, which were further partially converted to cyclic ether in subsequent annealing treatment. The effects of oxygen functionalization of carbon on HER performances of the resulting Pt/C catalysts after loading Pt particles were investigated. The results suggested that Pt loading on oxidized GP followed by treatment at 300 ℃ (Pt/GP-O-300) exhibited much better HER activity and stability than the unmodified (Pt/GP) and only oxidized (Pt/GP-O) samples. Pt/GP-O-300 delivered a lower overpotential of 144 mV at 10 mA cm−2 than Pt/GP (220 mV) and Pt/GP-O (183 mV). The time-dependent current density and accelerating durability testing analyses indicated Pt/GP-O-300 possess better stability than Pt/GP and Pt/GP-O. Overall, novel insights into the design of oxygen functional groups on carbon surface were provided, a promising strategy to enhance HER performance of future prepared Pt/C catalysts.

Thickness-dependent catalytic activity of hydrogen evolution based on single atomic catalyst of Pt above MXene

Hydrogen as the cleanest energy carrier is a promising alternative renewable resource to fossil fuels. There is an ever-increasing interest in exploring efficient and cost-effective approaches of hydrogen production. Recent experiments have shown that single platinum atom immobilized on the metal vacancies of MXenes allows a high-efficient hydrogen evolution reaction (HER). Here using ab initio calculations, we design a series of substitutional Pt-doped Ti n + 1C n T x (Ti n + 1C n T x -PtSA) with different thicknesses and terminations (n = 1, 2 and 3, T x = O, F and OH), and investigate the quantum-confinement effect on the HER catalytic performance. Surprisingly, we reveal a strong thickness effect of the MXene layer on the HER performance. Among the various surface-terminated derivatives, Ti2CF2-PtSA and Ti2CH2O2-PtSA are found to be the best HER catalysts with the change of Gibbs free energy ΔG H* ∼ 0 eV, complying with the thermoneutral condition. The ab initio molecular dynamics simulations reveal that Ti2CF2-PtSA and Ti2CH2O2-PtSA possess a good thermodynamic stability. The present work shows that the HER catalytic activity of the MXene is not solely governed by the local environment of the surface such as Pt single atom. We point out the critical role of thickness control and surface decoration of substrate in achieving a high-performance HER catalytical activity.

Surface modification of WO3 nanoparticles with Pt and Ru for VOCs sensors

• WO3 nanoparticles were fabricated by the thermolysis method, Pt and Ru as the active catalysts are loaded with the wet impregnation method. • The Pt/Ru-WO3 indicated the significant enhanced for sensitive response to acetone. • The power-law response to oxygen was observed. Ru is dominated by electron sensitization, while a major for Pt is reflected in its catalytic sensitization. • This study provides beneficial information and insights into the sensitization mechanism of bimetallic nanoparticles on MOS materials. The production of a large number of metal oxide semiconductor materials is more for design needs, while theoretical exploration is relatively less concerned. In this work, WO 3 nanoparticles were prepared by the tungstic acid thermolysis method, and the catalysts of Pt and Ru were loaded on the surface of nanoparticles with a wet impregnation method. As expected, the sensitive responses were enhanced significantly with the additional loading of Pt, which revealed that bimetallic loading could achieve better properties with a smaller loaded amount than single metal. According to the power-law response to oxygen and H 2 -TPR results, the sensitization mechanism of noble metals loaded WO 3 to acetone as the typical VOCs was investigated. The results showed that the sensing processes were dominated by oxygen adsorption behavior and there was no difference with the loading of Ru. Furthermore, the power-law coefficient n became smaller with Pt loading. It is proposed that oxygen adsorbates on the surface become more active due to Pt. We would like to propose further a perspective, i.e., polymetallic loading that utilizes the properties of different metals to achieve synergism. In this work, WO 3 nanoparticles were prepared by the tungstic acid thermolysis method, and the catalysts of Pt and Ru were loaded on the surface of nanoparticles with a wet impregnation method. Sensor devices were fabricated by the screen-printing technique, and the schematic drawing of sensor structure and a photograph of MOS sensor device were presented in graphical abstracts. The powders were mixed with prepared organic solutions and adhesive to obtain a printable paste, which was deposited on an aluminum substrate with interdigitated Au microelectrodes on the front side and Pt microheater on the backside. As expected, the sensitive response was enhanced significantly with the additional loading of Pt, which revealed that bimetallic loading could achieve better properties with a smaller loaded amount than single metals. The results showed that the sensing processes were dominated by oxygen adsorption behavior and there was no difference with the loading of Ru. Furthermore, the power-law coefficient n became smaller with Pt loading. It is proposed that oxygen adsorbates on the surface become more active due to Pt. We demonstrated that the sensing mechanism of the Ru-WO 3 and Pt/Ru-WO 3 sensors is not identical, and Ru is dominated by electron sensitization, while a major for Pt is reflected in its catalytic sensitization. Loaded metals combine with WO 3 to form a heterojunction layer, which enhances the ability of sensitive materials to regulate electrons. The catalytic activity of both metals was enhanced due to the synergistic effect of the bimetals. Consequently, this study provides beneficial information and insights into the sensitization mechanism of bimetallic nanoparticles on MOS materials, which can help us to tune further the bimetallic composition and catalytic activity for specific applications and pave the way for polymetallic loading studies.

Promoting effect of acid sites in hierarchical porous Pt/ZSM-5 catalysts for low-temperature removal of VOCs

A group of Pt/ZSM-5 catalysts with various SiO2/Al2O3 molar ratios was prepared and their catalytic activities for various VOCs catalytic oxidation were evaluated. It is found that for the deep catalytic oxidation of n-hexane and benzene, the Pt/ZSM-5(46) exhibits the highest activity by virtue of the balance between Pt0 content and Pt dispersion. The high Pt0 content and great dispersion of Pt in catalysts are beneficial for VOCs oxidation. However, as for deep catalytic oxidation of oxygen/nitrogen-containing VOCs, the strong and abundant acid sites benefits to their adsorption on the surface of catalysts, and Pt/ZSM-5(25) with the lowest SiO2/Al2O3 molar ratio exhibits the highest activity owing to the promoting effect of the acid sites. This comprehensive study exemplifies a promising strategy for the design and preparation of innovative catalysts applied to the low-temperature removal of VOCs.

Efficient and stable Pt/CaO-TiO2-Al2O3 for the catalytic dehydrogenation of cycloalkanes as an endothermic hydrocarbon fuel

The dehydrogenation of liquid hydrocarbon fuel is a potential endothermic reaction for the regenerative cooling of advanced aircraft. The high active and stable dehydrogenation catalyst plays a vital role in the catalytic heat exchange process. Herein, we show that a CaO-modified TiO2-Al2O3 supported Pt catalyst (Pt/CTA) is efficient and stable for the dehydrogenation of cycloalkanes (methylcyclohexane and decalin) under a supercritical condition. Adding an appropriate content of CaO (5 wt%) improves the catalyst durability. For the decalin dehydrogenation reaction (600 °C, 4 MPa, and WHSV = 208.8 h−1), the Pt/CTA maintains 27.9 wt% conversions at 600 min. For the methylcyclohexane dehydrogenation reaction (600 °C, 4 MPa, and WHSV = 188.4 h−1), the Pt/CTA maintains 42.6 wt% conversions at 600 min. The declines of cycloalkanes dehydrogenation conversion are < 7.0 % within 600 min, and no obvious sintering of Pt particles is observed. For a comparison, γ-Al2O3 supported Pt catalyst (Pt/A) exhibits poor catalytic activity and stability, and the conversion decreases to below 10 wt% at 180 min due to severe coke deposition and sintering of Pt particles over the catalysts. The characterization analyses demonstrate that the addition of CaO facilitates the formation of oxygen vacancy defects, thereby increasing the electron density of Pt particles (electronic effect) and promoting encapsulation of Pt particles (geometric effect). Furthermore, the addition of CaO reduces the acid amount and weakens the strength of acid sites over TiO2/Al2O3, inhibiting catalyst deactivation by mitigating coke formation. However, excessive CaO addition (10 wt%) rapidly decreases the surface area of the support, resulting in low dispersion and sintering of Pt particles, ultimately leading to poor catalytic activity and stability.

Electric metal contacts to monolayer blue phosphorus: electronic and chemical properties

The contact nature when monolayer blue phosphorus (blueP) interfaces with three transition metal electrodes (i.e., Pd, Ir, and Pt) was unraveled by the ab initio density functional theory calculations. Specifically, n-type Schottky contact is observed for Ir(111)-blueP, in contrast, p-type Schottky contacts are formed for Pd(111)- and Pt(111)-blueP. The Fermi level is pinned partially at metal-blueP interfaces due to two interfacial behaviors: one being the modification of metal work function caused by interface dipole formation ascribed to a redistribution of charges, and the other being the production of gap states that are dominated by P p-orbitals since the intralayer PP bonds are weakened by the interfacial metal-P interactions. The incorporation of metal substrates would also significantly alter the chemical properties of the adsorbed monolayer blueP. The binding strength of hydrogen can be enhanced by as much as 0.9 eV, which resulted from two parts: one is the charge transfer from metal substrate to monolayer blueP rendering a stronger HP coupling; the other is a strong interfacial interaction after the hydrogen adsorption. The free energy change of H adsorption onto Ir(111)-blueP is as low as 0.16 eV which is comparable to the most efficient catalyst of Pt. These findings would provide theoretical guidance for the future design of electronic devices based on blueP and exploration of its potential in novel catalysts for hydrogen evolution reaction.

Technological Aspects of Highly Selective Synthesis of Allyloxyalcohols—New, Greener, Productive Methods

Allyl ethers bearing free hydroxyl groups of CH2=CH-CH-O-A-OH type (hydroxyalkyl allyl ethers, allyloxyalcohols) are valuable chemicals in many environmentally friendly industrial applications. The development of technologically attractive methods for their production is necessary. The two pathways (L-L PTC and non-catalytic solvent-free conditions) were optimized for the highly selective and yield synthesis of 4-allyloxybutan-1-ol. Improvements in the PTC method (50% NaOH(aq), the equimolar ratio of NaOH to diol, cyclohexane as solvent) with a new highly selective and effective PT catalyst, i.e., Me(n-Oct)3N+Br− (0.3 mol%), resulted in 88% yield and 98% selectivity of 4-allyloxybutan-1-ol with minimal formation of allyl chloride hydrolysis by-products (&lt;1%). In turn, application of non-catalytic solvent-free conditions and the change in the key substrate with an excess of diol and use of solid NaOH solely led to a mono-O-allylation product with an excellent yield of 99% in a relatively short reaction time (3.5 h), with trace amounts of by-products (&lt;0.1%). This sustainable method is perfectly suitable for the synthesis on a larger scale (3 moles of the key substrate) and for the full O-allylation process.

Effect of the reductive treatment on the state and electrocatalytic behavior of Pt in catalysts supported on Ti0.8Mo0.2O2-C composite

Ti(1-x)MoxO2-carbon composites are promising new supports for Pt-based electrocatalysts in polymer electrolyte membrane fuel cells offering exciting catalytic properties and enhanced stability against electrocorrosion. Pt and the mixed oxide form a couple liable for strong metal-support interaction (SMSI) phenomenon, generally manifesting itself in decoration of the metal particles by ultrathin layers of the support material upon annealing under reductive conditions. The aim of this work is to evaluate the SMSI phenomenon as a potential strategy for tailoring the properties of the electrocatalyst. A 20 wt% Pt/50 wt% Ti0.8Mo0.2O2-50 wt% C electrocatalyst prepared on Black Pearls 2000 carbon functionalized with HNO3 and glucose was reduced at 250 °C in H2 in order to induce SMSI. The electrocatalytic properties and the stability of the reduced and the original catalysts were analyzed by cyclic voltammetry and COads stripping voltammetry. Structural investigations as well as X-ray photoelectron spectroscopy (XPS) measurements were performed in order to obtain information about the details of the interaction between the oxide and the Pt particles. The electrochemical experiments pointed out a small loss of the electrochemically active surface area of Pt in the reduced catalyst along with enhanced stability with respect to the original one, while structural studies suggested only a minimal decrease of the Pt dispersion. At the same time, hydrogen exposure experiments combined with XPS demonstrated the presence of Mo species directly adsorbed on the Pt surface. Thus, the properties of the reduced catalyst can be traced to decoration of the surface of Pt by Mo-containing species.

Heterojunction-Based Electron Donators to Stabilize and Activate Ultrafine Pt Nanoparticles for Efficient Hydrogen Atom Dissociation and Gas Evolution.

Platinum (Pt) is the most effective bench-marked catalyst for producing renewable and clean hydrogen energy by electrochemical water splitting. There is demand for high HER catalytic activity to achieve efficient utilization and minimize the loading of Pt in catalysts. In this work, we significantly boost the HER mass activity of Pt nanoparticles in Ptx /Co to 8.3 times higher than that of commercial Pt/C by using Co/NC heterojunctions as a heterogeneous version of electron donors. The highly coupled interfaces between Co/NC and Pt metal enrich the electron density of Pt nanoparticles to facilitate the adsorption of H+ , the dissociation of Pt-H bonds and H2 release, giving the lowest HER overpotential of 6.9 mV vs. RHE at 10 mA cm-2 in acid among reported HER electrocatalysts. Given the easy scale-up synthesis due to the stabilization of ultrafine Pt nanoparticles by Co/NC solid ligands, Ptx /Co can even be a promising substitute for commercial Pt/C for practical applications.

Heterojunction‐Based Electron Donators to Stabilize and Activate Ultrafine Pt Nanoparticles for Efficient Hydrogen Atom Dissociation and Gas Evolution

AbstractPlatinum (Pt) is the most effective bench‐marked catalyst for producing renewable and clean hydrogen energy by electrochemical water splitting. There is demand for high HER catalytic activity to achieve efficient utilization and minimize the loading of Pt in catalysts. In this work, we significantly boost the HER mass activity of Pt nanoparticles in Ptx/Co to 8.3 times higher than that of commercial Pt/C by using Co/NC heterojunctions as a heterogeneous version of electron donors. The highly coupled interfaces between Co/NC and Pt metal enrich the electron density of Pt nanoparticles to facilitate the adsorption of H+, the dissociation of Pt−H bonds and H2 release, giving the lowest HER overpotential of 6.9 mV vs. RHE at 10 mA cm−2 in acid among reported HER electrocatalysts. Given the easy scale‐up synthesis due to the stabilization of ultrafine Pt nanoparticles by Co/NC solid ligands, Ptx/Co can even be a promising substitute for commercial Pt/C for practical applications.