Dispersed Pd Research Articles

The performance and mechanism of HCHO oxidation on Pd/SiO2 catalysts with different Pd particle sizes

In general, for Pd-based catalysts, the smaller the Pd particles on the catalysts are, the better the activity for HCHO oxidation; this has solely been ascribed to the high Pd dispersion on the catalysts’ surface. However, the Pd site effect on HCHO oxidation is still not clear. In this work, we regulated the proportions of different Pd sites on Pd/SiO2 catalysts by high-temperature treatment of the carriers. With the increase in treatment temperature, the dominant active sites on Pd particles changed from terraces to steps and finally to corner sites. The corner sites were found to be important for oxygen activation, which led to the HCHO catalytic oxidation performance increasing in the order Pd/SiO2, Pd/SiO2(500) and Pd/SiO2(800). It is worth noting that in the reaction pathway for HCHO oxidation, formate was the primary intermediate on the Pd/SiO2 catalyst. However, in addition to formate, CO species were also detected on the Pd/SiO2(500) and Pd/SiO2(800) catalysts. DFT results confirmed that the corner sites were more favorable for the HCHO → CHO → CO pathway, compared to the terrace sites. This work elucidates the effect of Pd sites on the HCHO oxidation mechanism over Pd/SiO2 catalysts, providing valuable insights for the design of highly active catalysts.

Construction of Pd@K-Silicalite-1 via in situ encapsulation and alkali metal modification for catalytic elimination of formaldehyde at room temperature

The Silicalite-1-encapsulated Pd catalyst with alkali metal K modification (Pd@K-Silicalite-1) was prepared via the hydrothermal method with ethylenediamine as ligand and KOH as precursor of K promoter. The introduction of K partially replaced H of silanol in Silicalite-1 and induced the formation of Si-O-K-Pd species, which were beneficial for the improvement of Pd dispersion. The Pd nanoparticles with a size of ca. 1.9 nm were uniformly encapsulated in the matrix of Silicalite-1 zeolite. The catalytic activity of Pd@K-Silicalite-1 was much better than those of Pd/Silicalite-1 and Pd@Silicalite-1 for HCHO oxidation, HCHO conversion could reach 100 % over Pd@K-Silicalite-1 (Pd content = 0.15 wt%) at room temperature under space velocity (SV) of 120,000 mL/(g × h) and relative humidity (RH) of 35 %. Based on the results of various characterization techniques, one can conclude that the improvement in catalytic activity of Pd@K-Silicalite-1 was attributable to high dispersion and small size of Pd NPs and enhanced HCHO adsorption capacities. In addition, we investigated the reaction mechanism of HCHO oxidation over the Pd@K-Silicalite-1 catalyst by in situ DRIFTS spectra. This work provides some guidance on developing high-performance catalysts for HCHO elimination via in situ encapsulation and alkali metal modification.

Light‐off Performance of Three‐Way Catalysts Before and After Accelerated Aging Test with an Engine‐Dynamometer

AbstractThis study demonstrates the reaction behavior during the purification of model automotive exhaust gases over Pd catalysts before and after thermal degradation. In particular, to investigate the relationship between the Pd state and the reaction behavior of Pd/Al2O3 and Pd/CeO2−ZrO2 (CZ), operando X‐ray absorption spectroscopy measurements were performed during purifying exhaust gases over real and model catalysts mimicking the degradation of Pd particles and CZ supports after accelerated aging tests. The NO reduction activity of the aggregated Pd metal species was as high as that of the highly dispersed Pd species, but hydrocarbon (HC) poisoning was significantly enhanced by the aggregation of Pd metal particles caused by thermal aging. The existence of a three‐phase boundary (TPB) between the CZ, the Pd particles, and the gas phase strongly affected the catalytic activity at low temperatures, and the presence of a sufficient TPB facilitated the combustion of unburned HCs owing to the oxygen storage performance of CZ. Thus, the TPB reduced the poisoning of the precious metal surface by HC species at low temperatures. Therefore, the findings of this study will facilitate the development of next‐generation gas purification catalysts with high activity and durability.

Enhanced hydroisomerization of n-heptane over bifunctional catalysts with highly dispersed Pd nanoparticles supported on H-Yβ composite zeolite

Enhanced catalytic hydroisomerization efficiency and iso-alkanes selectivity by exploring the bifunctional zeolite-supported metal catalysts at the nanoscale are of great important in petrochemical and coal chemical industries. Herein, we develop a simple two-step strategy for introducing intracrystalline and intercrystalline mesopores in H-Yβ by in-situ compositing and loading Pd nanoparticles (NPs, ∼2.2 nm) through an incipient wetness impregnation process followed by mild oxidation–reduction treatment. Especially, the Pd@H-Yβ catalyst with synergistic acid sites and highly dispersed Pd NPs inherits the large surface area, high crystallinity and graded mesoporous channels, and strong thermal and hydrothermal stability. As a demonstration, Pd@H-Yβ with extremely low Pd NPs loading amount of 0.2 wt% used for catalytic hydroisomerization of n-heptane (n-C7) by cascade dehydrogenation and hydrogenation on Pd NPs and isomerization on accessible acid sites, and exhibits an extraordinarily yield of i-heptane (i-C7,74.7 %) compared to the conventional Pd@H-Y (49.1 %) and Pd@H-β (33.7 %) at 280 °C for 3 h under 1 MPa initial hydrogen pressure (IHP). Furthermore, first-principle calculations reveal that the high catalytic activity of Pd@H-Yβ originates from the active hydrogen (H…H and/or H+) transfer by the facile H2 dissociation. The diffusion limitations of intermediates and secondary cracking reactions are effectively weakened due to intrinsic mesoporous channels in Pd@H-Yβ, which still maintains high catalytic activity after 5 times recycles. These findings provide a rational design strategy of bifunctional catalysts with adjustable metal–acid active sites for low-molecular reactants hydroisomerization in industrial application.

The carrier effect of ternary solid solution derived by trimetallic CeZrNi MOFs on the Pd dispersion stability for NGVs exhaust purification

AbstractThis article was the first to prepare CeZrNiOx ternary solid solution using CeZrNi BDC MOFs as a template, and investigate its effect on improving the dispersion stability of Pd components in three‐way catalysts and the catalytic performance of natural gas exhaust purification. The experimental results indicated that CeZrNiOx derived from CeZrNi‐BDC MOFs had a stable solid solution uniform structure and relatively good thermal stability of the porous structure. Therefore, the thermal stability of Pd/CZN−M derived from CeZrNi BDC MOFs was significantly better than that of Pd/CZN−C prepared by citric acid complexation method. The PdO particle size of Pd/CZN−M before and after thermal aging was only about 2.0 and 4.5 nm, respectively. At GHSV50000 ml/(g⋅h), the T90 of aged Pd/CeZrNiOx for CH4, NO, and CO reached 410, 370, and 175 °C, respectively, showing better three‐way catalytic (TWC) activity than reported in existing literature. In addition, CeZeNiOx carriers derived from MOFs also enhanced the co‐activation ability of NO and CH4, and exhibited certain activity in the low‐temperature self‐decomposition reaction of NO, thus showing significant advantages in the TWC catalytic activity of NGVs. This work would provide a new method for preparing NGVs exhaust TWC catalysts with high dispersion stability.

Reversible hydrogenation and dehydrogenation of benzene for hydrogen storage on highly dispersed Pd/γ-Al2O3 catalyst

The research and development of efficient catalyst is the key to achieving high-capacity hydrogen storage in liquid organic hydrogen carriers (LOHCs). The highly dispersed Pd/γ-Al2O3 catalysts with few-atom Pd were prepared by impregnation method using HNO3 as promoter. The hydrogen storage capacity of the benzene/cyclohexane hydrogen carriers was further investigated by vapor phase benzene hydrogenation and cyclohexane dehydrogenation reactions over the studied Pd/γ-Al2O3 catalysts. The results showed that the metal Pd was the active centers for the benzene hydrogenation/cyclohexane dehydrogenation reactions. The addition of HNO3 can effectively promote the metal Pd to be highly dispersed, thus improving the Pd atoms utilization and reducing the Pd dosage. Meanwhile, the strongly electronic effects between the highly dispersed Pd species and the Al2O3 support promoted the electron-deficient Pdδ+ sites to be formed, which enhanced the adsorption and activation ability for the reactants molecules. The benzene conversion on the Pd/γ-Al2O3 catalyst with a metallic Pd loading of 1.0 wt% reached 97.51 % at 200 °C. While the cyclohexane conversion reached 90.94 % at 400 °C with the actual hydrogen storage capacity of 6.54 wt%, which provided an effective idea for large-scale storage and transportation of H2 based on LOHCs.

Assessment of cardiac arrhythmias, P wave and QT dispersion in systemic sclerosis

Cardiac involvement in systemic sclerosis (SSc) is significant cause of SSc-related mortality. The objective of the study was to assess cardiac arrhythmias, P wave and QT dispersion in SSc patients. 40 SSc patients and 40 healthy participants who had similar sociodemographic characteristics with the patients were enrolled in the study. P wave dispersion (Pd), QT dispersion (QTd), and corrected QT (QTc) dispersion (QTcd) were calculated by measuring maximum (max) and minimum (min) of P wave, QT interval, QTc in 12-leads electrocardiography (ECG). Cardiac arrhythmias and conduction disorders were assessed by ECG and Holter-ECG. The mean age of SSc patients (92.5% of females) was 50.9±13.9 years similar with the healthy group (51.4±8.9). Abnormal ECG findings were found in 27.5% of SSc patients and remarkably higher in comparison to the healthy participants (p=0.019). The most frequently reported abnormal ECG findings were left anterior fascicular block (15%), ventricular premature beat (10%) and first-degree atrioventricular heart block (5%). The comparison of dispersion showed no statistically important difference in Pd between two groups (p=0.69) while QTd, QTc, QTcd, QTc min, and QTc max were markedly prolonged in patients with SSc (p=0.039; p<0.001; p=0.021; p<0.001; p<0.001, respectively). The assessment of Holter-ECG demonstrated that supraventricular tachycardia was frequently detected in patients with SSc (22.5% vs 2.5%; p=0.007). This study indicated a significantly elevated incidence of abnormal ECG results and SVT, an arrhythmia not typically identifiable through standard ECG but detectable via Holter monitoring, in patients with SSc. In the study, QTd, QTc, and QTcd intervals were significantly longer in SSc patients, which may indicate a susceptibility to arrhythmias.

Atomically Dispersed Pd on ZrO2 for Efficient Nitrite Electroreduction to Ammonia

Electrochemical conversion of NO2- to NH3 (NO2RR) provides an appealing route to enable effective wastewater treatment and sustainable NH3 production. Herein, we report that atomically dispersed Pd on ZrO2 substrate...

Regulation of a Ni3Sn2 intermetallic catalyst using highly dispersed Pd species to boost propyne semi-hydrogenation

Introduction of highly dispersed Pd into well-regulated structures of a Ni3Sn2 intermetallic catalyst contributes to excellent catalytic performance for propyne semi-hydrogenation.

Uniformly Dispersed Nano Pd-Ni Oxide Supported on Polyporous CeO2 and Its Application in Methane Conversion of Tail Gas from Dual-Fuel Engine

The development of catalysts for low-temperature methane combustion is crucial in addressing the greenhouse effect. An effective industrial catalyst strategy involves optimizing noble metal utilization and boosting metal–metal interaction. Here, the PdNi-H catalyst was synthesized using the self-assembly method, achieving the high dispersion and close proximity of Pd and Ni atoms compared to the counterparts prepared by the impregnation method, as confirmed by EDS mapping. The XRD and TEM results revealed Pd2+ and Ni2+ doping within the CeO2 lattice, causing distortions and forming Pd-O-Ce or Ni-O-Ce structures. These structures promoted oxygen vacancy formation in CeO2, and this was further confirmed by the Raman and XPS results. Consequently, the PdNi-H catalyst demonstrated an excellent redox ability and catalytic activity, achieving lower ignition and complete methane burning temperatures at 282 and 387 °C, respectively. The highly dispersed PdNi species played a pivotal role in activating methane for enhanced redox ability. Additionally, the narrow size distribution range contributed to more vacancies on the surface of CeO2, as confirmed by the XPS results, thereby facilitating the activation of gas phase oxygen to form oxygen species (O2−). This collaborative catalytic approach presents a promising strategy for developing efficient and stable methane combustion catalysts at low temperatures.

Fabrication modulation of lignin-derived carbon nanosphere supported Pd nanoparticle via lignin fractionation for improved catalytic performance in vanillin hydrodeoxygenation

Nano-lignin presents great potential in advanced carbon materials preparation since it integrates the advantages of nanomaterials as well the preferable properties of lignin (e.g. high carbon content and highly aromatic structure). Herein, lignin-derived carbon nanosphere supported Pd catalysts (Pd@LCNS) were prepared via a two-step carbonization of Pd2+ adsorbed lignin nanospheres (LNS) and applied in vanillin hydrodeoxygenation. The effect lignin heterogeneity on the synthesis of Pd@LCNS as well as its catalytic performance was further investigated through the synthesis of Pd@LCNS using three lignin fractions with different molecular weight. The results showed that the three Pd@LCNSs exhibited significant differences in the morphology of both carbon support and Pd nanoparticles. Pd@LCNS-3 prepared from high molecular weight lignin fraction (L-3) presented stable carbon nanosphere support with the smallest particle size (∼150 nm) and the highest Pd loading amount (3.78 %) with the smallest Pd NPs size (∼1.6 nm). Therefore, Pd@LCNS-3 displayed superior catalytic activity for vanillin hydrodeoxygenation (99.34 % of vanillin conversion and 99.47 % of 2-methoxy-4-methylphenol selectivity) at 90 °C without H2. Consequently, this work provides a sustainable strategy to prepare uniformly dispersed lignin-based carbon-supported Pd catalyst using high molecular weight lignin as the feedstock and further demonstrate its superior applicability in the selective transfer hydrogenation of vanillin.

Understanding the reversible and irreversible deactivation of methane oxidation catalysts

Catalytic oxidation is a promising technology for controlling methane emissions from natural gas engines, but fast and severe deactivation prevents implementation. We investigated a commercial Pd on alumina oxidation catalyst under realistic conditions and identified two deactivation phenomena: fast, reversible inhibition and slow, irreversible loss of active sites. The loss of active sites occurs only during methane conversion, fortunately a brief oxygen cut-off is enough to regenerate the catalyst. Both types of deactivation increase the reduction temperature of PdO. From 36 kinetic experiments we propose a simple kinetic model encompassing both types of deactivation. The inhibition is confirmed to be due to water coverage of the active sites whereas dispersion of Pd on the surface is the cause of the irreversible loss of active sites. The new insight shows a pathway toward designing more durable catalysts for complete methane oxidation.

Photocatalytic production of ethylene and propionic acid from plastic waste by titania-supported atomically dispersed Pd species

Current chemical recycling of bulk synthetic plastic, polyethylene (PE), operates at high temperature/pressure and yields a complex mixture of products. PE conversion under mild conditions and with good selectivity toward value-added chemicals remains a practical challenge. Here, we demonstrate an atomic engineering strategy to modify a TiO 2 photocatalyst with reversible Pd species for the selective conversion of PE to ethylene (C 2 H 4 ) and propionic acid via dicarboxylic acid intermediates under moderate conditions. TiO 2 -supported atomically dispersed Pd species exhibits C 2 H 4 evolution of 531.2 μmol g cat −1 hour −1 , 408 times that of pristine TiO 2 . The liquid product is a valuable chemical propanoic acid with 98.8% selectivity. Plastic conversion with a C 2 hydrocarbon yield of 0.9% and a propionic acid yield of 6.3% was achieved in oxidation coupled with 3 hours of photoreaction. In situ spectroscopic studies confirm a dual role of atomic Pd species: an electron acceptor to boost charge separation/transfer for efficient photoredox, and a mediator to stabilize reaction intermediates for selective decarboxylation.

Pd-doped Ni nanocatalyst with high Pd utilization for semi-hydrogenation of phenylacetylene at ambient conditions

Semi-hydrogenation of phenylacetylene to styrene is an essential process in the expanding polystyrene industry. Despite Pd-based catalysts have been widely used, challenges like styrene over-hydrogenation and high cost remain to be addressed. Herein, a Pd-doped Ni nanocatalyst (Pd0.1/Ni1/Al2O3) with excellent Pd utilization was successfully developed for semi-hydrogenation of phenylacetylene, delivering a high conversion of >99 % with 95 % selectivity to styrene at ambient temperature and pressure (25 °C, 1 atm H2). The boosted catalytic activity might be ascribed to the mesoporous Al2O3 with large surface area, and the enhanced selectivity is due to the reduced electron density and improved dispersion of Pd derived from Ni-Pd interaction. Furthermore, the catalyst exhibits excellent stability for enduring 6 cycles. This work provides an efficient and practical strategy to develop cost-effective, high-performance and recyclable catalysts for various selective hydrogenation reactions in fundamental and applied research.

Carbon-supported Pd/NiO-CoOx nanoparticles for highly selective and stable 1-nitroanthraquinone hydrogenation

1-aminoanthraquinone has numerous applications in chemical industry, for example, it is an important intermediate for producing anthraquinone dyes. In this work, Pd/NiO/C, Pd/CoOx/C, and Pd/NiO-CoOx/C (C-carbon black) are prepared by room-temperature hydrazine hydrate and replacement reduction methods. All as-prepared catalysts have been characterized by XRD, SEM, TEM, HRTEM, XPS, STEM-EDX elemental mapping and line-scanning et al., The Pd-related species are highly dispersed on the nickel, cobalt or nickel-cobalt oxide nanoparticles (NPs), the interaction of Pd–NiO (or CoOx, NiO-CoOx) is present. Pd/NiO-CoOx/C provides 99.2 % conversion of 1-nitroanthraquinone and 91.0 % selectivity to 1-aminoanthraquinone for 1-nitroanthraquinone hydrogenation under the following reaction conditions: H2 pressure-3.0 MPa, 60 °C, 4 h. The catalytic behaviors of Pd/NiO-CoOx/C for 1-nitroanthraquinone hydrogenation are much better than Pd/NiO/C and Pd/CoOx/C mainly due to the interaction of Pd–NiO-CoOx, synergy effect of Pd and NiO-CoOx, and high Pd dispersion.

The First Application of Palladium–Phosphorus Catalysts in the Direct Synthesis of Hydrogen Peroxide: Reasons for the Promoting Action of Phosphorus

The main reasons for the promoting effect of phosphorus on the properties of Pd–P/ZSM-5 palladium catalysts in the direct synthesis of H2O2 from H2 and O2 under mild conditions are considered based on data from X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and inductively coupled plasma mass spectrometry (ICP MS). It is shown that the introduction of phosphorus into the composition of the catalyst affects the dispersity, the electronic state of palladium in the surface layer, and the surface concentration of phosphate and phosphite ions. An increase in the H2O2 yield is favored by an increase in the dispersion of Pd–P-catalysts, inhibition of the side process of H2O2 decomposition by surface phosphate and phosphite ions, and a decrease in the solubility of hydrogen in solid solutions of phosphorus in palladium.

Interface Charge Distribution Engineering of Pd-CeO2 /C for Efficient Carbohydrazide Oxidation Reaction.

Carbohydrazide electrooxidation reaction (COR) is a potential alternative to oxygen evolution reaction in water splitting process. However, the sluggish kinetics process impels to develop efficient catalysts with the aim of the widespread use of such catalytic system. Since COR concerns the adsorption/desorption of reactive species on catalysts, the electronic structure of electrocatalyst can affect the catalytic activity. Interface charge distribution engineering can be considered to be an efficient strategy for improving catalytic performance, which facilitates the cleavage of chemical bond. Herein, highly dispersed Pd nanoparticles on CeO2 /C catalyst are prepared and the COR catalytic performance is investigated. The self-driven charge transfer between Pd and CeO2 can form the local nucleophilic and electrophilic region, promoting to the adsorption of electron-withdrawing and electron-donating group in carbohydrazide molecule, which facilitates the cleavage of C-N bond and the carbohydrazide oxidation. Due to the local charge distribution, the Pd-CeO2 /C exhibits superior COR catalytic activity with a potential of 0.27 V to attain 10 mA cm-2 . When this catalyst is used for energy-efficient electrolytic hydrogen production, the carbohydrazide electrolysis configuration exhibits a low cell voltage (0.6 V at 10 mA cm-2 ). This interface charge distribution engineering can provide a novel strategy for improving COR catalytic activity.

Pd "Kills Two Birds with One Stone" for the Synthesis of Catalyst: Dual Active Sites of Pd Triggers the Kinetics of O2 Electrocatalysis.

Noble metal-based catalyst, despite their exorbitant cost, are the only successful catalyst for bifunctional oxygen electrocatalysis owing to their capability to drive forward the reaction rate kinetically. Therefore, it is desirable to diminish the noble metal loading without any compromise in the catalyst performance. In this study, the aim to achieve two goals with one action via a single-step route to have ultra-low loading of Pd in the catalyst. The Pd is used as a catalyst for C─C bond formation followed by complexation reactions or vice versa, in conventional Suzuki-Miyaura cross-coupling (SMCC) reaction, which yields a Pd-based porous organic polymer. Interestingly, it is found that dispersed Pd nanocluster (PdNC ) is present together with Pd single atom doped into nanocarbon (Pd-NC) matrix in the catalyst (PdNC /Pd-NC800 ) that obtained after pyrolysis of the porous polymer. The catalyst exhibits remarkable bifunctional activity and durability towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Further, it is studied that the in situ attenuated total reflection infrared (ATR-IR) spectroscopy at different electrochemical potentials during ORR and OER to observe the reaction intermediates. The homemade zinc-air battery with the catalyst displayed great performance, establishing the significance of PdNC /Pd-NC800 as a bifunctional oxygen electrocatalyst.

Highly Efficient Cauliflower-like Palladium-Loaded Porous MOF as a Robust Material for the Degradation of Organic Dyes.

A series of porous MOF materials, viz., Pdx@IRMOF-9 (x = 2, 5, and 10%) were synthesized by loading varying concentrations of Pd(II) on IRMOF-9. The synthesized MOF materials were characterized by ltravioletisible (UV-Vis) spectroscopy, Fourier transform Infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), Brunauer-Emmett-Teller (BET), and scanning electron microscopy (SEM) analyses. UV, FT-IR, and PXRD data of Pd(II)@IRMOF-9 were found to be in line with those of IRMOF-9, which suggests that the structure of the IRMOF-9 remained intact upon Pd(II) loading. Surface morphology of IRMOF-9 showed sheet-like structures, and upon incorporation of Pd(II) to IRMOF-9, porous cauliflower-shaped MOFs were obtained. The SEM area mapping of Pd10%@IRMOF-9 confirmed the homogeneous dispersion of Pd(II) on IRMOF-9. BET measurements suggested an increase in the surface area as well as pore size upon incorporation of Pd(II) on IRMOF-9. Due to high porosity and high petal density, Pd10%@IRMOF-9 demonstrated degradation of seven organic dyes, namely, orange G, methylene blue, methyl orange, congo red , methyl red, rhodamine 6G, and neutral red. It showed excellent results with >90% dye degradation efficiency in case of cationic, anionic as well as neutral dyes. Degradation of organic dyes followed the pseudo-first-order kinetics. Kinetic parameters, KM and Vmax, were calculated using the double reciprocal Lineweaver-Burk plot and were found to be 13.2 μM and 26.68 × 10-8 M min-1, respectively. Recyclability studies of heterogeneous Pd10%@IRMOF-9 demonstrated the degradation of CR dye for five consecutive cycles without significant loss of its catalytic activity. Herein, a robust and efficient material for the degradation of organic dyes has been developed and demonstrated.

Hybridization of covalent organic frameworks and photosensitive metal‐organic rings: A new strategy for constructing supramolecular Z‐scheme heterostructures for ultrahigh photocatalytic hydrogen evolution

AbstractThe rational design of Z‐scheme heterojunction photosystems based on covalent organic frameworks (COFs) is a promising strategy for harnessing solar energy for hydrogen conversion. Herein, a direct Z‐scheme single‐atom photocatalyst based on COF and metal‐organic ring has been constructed through the supramolecular interactions of coral‐like COF (S‐COF) and photosensitized Pd2L2 type metal‐organic ring (MAC‐FA1). The MAC‐FA1/S‐COF heterojunction exhibits good light absorption, efficient charge separation and transfer, slow electron‐hole recombination, and highly dispersed Pd active sites, enabling an efficient and stable H2 evolution reaction. The optimized 4% MAC‐FA1/S‐COF achieves an H2 evolution rate of 100 mmol g−1 h−1 within 5 h and obtains a total accumulated turn‐over number relative to Pd (TONPd) of 437,685 within 20 h, far superior to S‐COF, MAC‐FA1, M‐5/S‐COF, Pd/S‐COF, and M‐5/Pd/S‐COF, which is one of the highest records among COF‐based photocatalysts for solar‐driven H2 evolution. This is the first work to incorporate photosensitized metal‐organic rings/cages into porous crystalline COFs to form a supramolecular Z‐scheme heterojunction, which has significant potential as a high‐performance photocatalyst for solar‐driven H2 production.