Proton-coupled Electron Transfer Research Articles

Heterometallic Transition Metal Oxides Containing Lewis Acids as Molecular Catalysts for the Reduction of Carbon Dioxide to Carbon Monoxide with Bimodal Activity.

Electrocatalytic CO2 reduction (e-CO2RR) to CO is replete with challenges including the need to carry out e-CO2RR at low overpotentials. Previously, a tricopper-substituted polyoxometalate was shown to reduce CO2 to CO with a very high faradaic efficiency albeit at -2.5 V versus Fc/Fc+. It is now demonstrated that introducing a nonredox metal Lewis acid, preferably GaIII, as a binding site for CO2 in the first coordination sphere of the polyoxometalate, forming heterometallic polyoxometalates, e.g., [SiCuIIFeIIIGaIII(H2O)3W9O37]8-, leads to bimodal activity optimal both at -2.5 and -1.5 V versus Fc/Fc+; reactivity at -1.5 V being at an overpotential of ∼150 mV. These results were observed by cyclic voltammetry and quantitative controlled potential electrolysis where high faradaic efficiency and chemoselectivity were obtained at -2.5 and -1.5 V. A reaction with 13CO2 revealed that CO2 disproportionation did not occur at -1.5 V. EPR spectroscopy showed reduction, first of CuII to CuI and FeIII to FeII and then reduction of a tungsten atom (WVI to WV) in the polyoxometalate framework. IR spectroscopy showed that CO2 binds to [SiCuIIFeIIIGaIII(H2O)3W9O37]8- before reduction. In situ electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) with pulsed potential modulated excitation revealed different observable intermediate species at -2.5 and -1.5 V. DFT calculations explained the CV, the formation of possible activated CO2 species at both -2.5 and -1.5 V through series of electron transfer, proton-coupled electron transfer, protonation and CO2 binding steps, the active site for reduction, and the role of protons in facilitating the reactions.

Tuning Energetics of 2 e-/2H+ PCET Properties with Model Ru-bisamido Complexes.

Most redox processes that break/form bonds involve net 2e- changes, and many are coupled to protons. Yet most proton-coupled electron transfer (PCET) studies focus on 1e-/1H+ reactions. Reported here is a family of molecular models that undergo tunable 2e-/2H+ redox changes. Complexes [(X2bpy)RuII(en*)2](PF6)2 and [(X2bpy)RuIV(en*-H)2](PF6)2 have been synthesized with bpy=2,2'-bipyridine with 4,4'-subtitutions X=-NMe2, -OMe, -Me, -H, -CF3; and en*=2,3-dimethyl-2,3-butanediamine. They have been characterized by IR, UV-vis, and NMR spectroscopies, XRD, electrochemistry, mass spectrometry, DFT and (TD)DFT computations. The introduction of electron-withdrawing and donating groups at the 4,4'-position of the bpy ligand affects the complexes' redox potentials, pKa's, and Bond Dissociation Free Energies (BDFEs) of the N-H bonds in the en* ligands. The average BDFEs for the overall 2e-/2H+ PCET span over 5 kcal/mol. Notably, these complexes all show marked potential inversion over an extended range, ΔpKa>25 units and ΔE0>1.4 V. Potential inversion remains despite the electronic influence of bpy's substitutions which regulate N-H properties several bonds apart by trans-effect over dπ-molecular orbitals at the Ru center. The experimental and computational results presented in this work support the presence of strong coupling between electrons and protons, for modelling insights of 2e-/2H+ transfer reactivity.

Acidic and Alkaline pH Controlled Oxygen Reduction Reaction Pathway over Co‐N4C Catalyst

AbstractEnhanced oxygen reduction reaction (ORR) kinetics and selectivity are crucial to advance energy technologies like fuel cells and metal–air batteries. Single‐atom catalysts (SACs) with M‐N4/C structure have been recognized to be highly effective for ORR. However, the lack of a comprehensive understanding of the mechanistic differences in the activity under acidic and alkaline environments is limiting the full potential of the energy devices. Here, a porous SAC is synthesized where a cobalt atom is coordinated with doped nitrogen in a graphene framework (pCo‐N4C). The resulting pCo‐N4C catalyst demonstrates a direct 4e− ORR process and exhibits kinetics comparable to the state‐of‐the‐art (Pt/C) catalyst. Its higher activity in an acidic electrolyte is attributed to the tuned porosity‐induced hydrophobicity. However, the pCo‐N4C catalyst displays a difference in ORR activity in 0.1 m HClO4 and 0.1 m KOH, with onset potentials of 0.82 V and 0.91 V versus RHE, respectively. This notable activity difference in acidic and alkaline media is due to the protonation of coordinated nitrogen, restricted proton coupled electron transfer (PCET) at the electrode/electrolyte interface. The effect of pH over the catalytic activity is further verified by Ab‐initio molecular dynamics (AIMD) simulations using density functional theory (DFT) calculations.

Manganese Doped‐Nitrogenated Carbon as an Efficient Catalyst for Acidic Electrocatalytic Reduction of CO2

AbstractRenewable electricity‐driven CO2 electroreduction to value‐added chemicals is a feasible approach to alleviate both environmental and energy issues. However, CO2 reduction reaction (CO2RR) systems in alkaline electrolytes are constrained by intrinsic limitations such as salt accumulation that impede further industrialization. Herein, an atomically dispersed Mn doped‐nitrogen carbon (AD MnNC) catalyst is developed to electrochemically reduce CO2 to CO in both neutral and acidic media. Benefiting from well‐dispersed MnNx sites, the maximum CO Faradaic efficiency (FECO) reaches ≈100% at −0.73 V versus reversible hydrogen electrode (RHE) with CO current density (JCO) of 20.4 mA cm−2 in neutral 0.5 m KHCO3. Due to diminished *H adsorption, AD MnNC achieves a FECO of 85.3% at pH 2.0, effectively suppressing the hydrogen evolution reaction (HER) in an acidic electrolyte. The mechanistic study reveals that AD MnNC accelerates the production of *COOH intermediates through a proton‐coupled electron transfer (PCET) pathway and thus promotes CO formation.

Tailoring the selective generation of high-valent cobalt-oxo by asymmetrically coordinated single-atom cobalt-activated peracetic acid for efficient water decontamination

The novel nonradical Fenton-like oxidation based on high-valent cobalt-oxo [CoIVO] species is a promising candidate for selectively removing emerging organic contaminants (EOCs) in complex water; however, efficient and targeted generation of CoIVO is hampered by the high Co-3d orbital occupancy and high bond dissociation energy of deprotonation. Herein, an O doping strategy to construct asymmetric coordination (CoN3O) in Co single-atom catalyst (Co-SAC) is developed to steer peracetic acid (PAA) activation for selectively generating CoIVO. Theoretical calculations suggest that asymmetric coordination of CoN3O could induce significant electron delocalization around Co centers, thus promote adsorption and peroxy O–O bond cleavage of PAA. The asymmetric electronic structure also exerts an additional local electric field, which favors the cleavage of O–H bond via a proton-coupled electron transfer pathway for subsequent CoIVO generation. Consistent with the theoretical prediction, the established CoN3O/PAA system exhibits admirable Fenton-like activity in degrading various EOCs to low-toxicity intermediates through exclusive generation of CoIVO, greatly reducing potential environmental risks. Our work provides a fundamental understanding of the structure–activity–selectivity relationships at an atomic level and provides a design guide to develop advanced CoIVO-involved Fenton-like catalyst for more extensive applications.

Nonadiabatic Proton-Coupled Electron Transfer at a Graphitic Surface Immobilized Cobalt Porphyrin

Nonadiabatic Proton-Coupled Electron Transfer at a Graphitic Surface Immobilized Cobalt Porphyrin

Graphene with suitable-size nitrogen-doped cavity being an excellent photocatalyst for proton-coupled electron transfer in water splitting

Aiming to attain porous carbon nitride photocatalysts with high specific surface area, abundant active sites, broad absorption range and effective electron-hole separation, we remove carbon rings from graphene and replace all the edge carbon atoms of the cavity with nitrogen atoms. The accurate electronic structures and exciton properties of the proposed materials are revealed by the ab initio many-body Green's function theory. Computational results show that the absorption of the designed materials can cover both the visible and the near-infrared light region. The exciton binding energies of the materials are one order of magnitude lower than those of the typical two-dimensional photocatalyst graphitic carbon nitride. Due to the formation of hydrogen bonds between pyridinic nitrogen atoms and water molecules during water splitting, the key excited-state proton-coupled electron transfer reactions are barrierless. These findings could serve as guidelines for the realization of high-performance metal-free two-dimensional photocatalysts.

Enhancing Compatibility of Two-Step Tandem Catalytic Nitrate Reduction to Ammonia Over P-Cu/Co(OH)2.

Electrochemical nitrate reduction reaction (NO3RR) is a promising approach to realize ammonia generation and wastewater treatment. However, the transformation from NO3 - to NH3 involves multiple proton-coupled electron transfer processes and by-products (NO2 -, H2, etc.), making high ammonia selectivity a challenge. Herein, a two-phase nanoflower P-Cu/Co(OH)2 electrocatalyst consisting of P-Cu clusters and P-Co(OH)2 nanosheets is designed to match the two-step tandem process (NO3 - to NO2 - and NO2 - to NH3) more compatible, avoiding excessive NO2 - accumulation and optimizing the whole tandem reaction. Focusing on the initial 2e- process, the inhibited *NO2 desorption on Cu sites in P-Cu gives rise to the more appropriate NO2 - released in electrolyte. Subsequently, P-Co(OH)2 exhibits a superior capacity for trapping and transforming the desorbed NO2 - during the latter 6e- process due to the thermodynamic advantage and contributions of active hydrogen. In 1m KOH + 0.1m NO3 -, P-Cu/Co(OH)2 leads to superior NH3 yield rate of 42.63mgh- 1cm- 2 and NH3 Faradaic efficiency of 97.04% at -0.4V versus the reversible hydrogen electrode. Such a well-matched two-step process achieves remarkable NH3 synthesis performance from the perspective of optimizing the tandem catalytic reaction, offering a novel guideline for the design of NO3RR electrocatalysts.

Accelerated Proton-Coupled Electron Transfer via Engineering Palladium Sub-Nanoclusters for Scalable Electrosynthesis of Hydrogen Peroxide.

Electrosynthesis of H2O2 from oxygen reduction reaction via a two-electron pathway is vital as an alternative for the energy-intensive anthraquinone process. However, this process is largely hindered in neutral and alkaline conditions due to sluggish kinetics associated with the transformation of intermediate O2* into OOH* via proton-coupled electron transfer sourced from slow water dissociation. Herein, we developed Pd sub-nanoclusters on the nickel ditelluride nanosheets (Pd SNCs/NiTe2) to enhance the performance of H2O2 electrosynthesis. The newly-developed Pd SNCs/NiTe2 exhibited a H2O2 selectivity of as high as 99% and a positive shift of onset potential up to 0.81 V. Combined theoretical calculations and experimental studies (e.g., X-ray absorption and attenuated total reflectance-Fourier transform infrared spectra measurements) revealed that the Pd sub-nanoclusters supported by NiTe2 nanosheets efficiently reduced the energy barrier of water dissociation to generate more protons, facilitating the proton feeding kinetics. When used in a flow cell, Pd SNCs/NiTe2 cathode efficiently produced H2O2 with a maximum yield rate of 1.75 mmol h-1 cm-2 and current efficiency of 95% at 100 mA cm-2. Further, an accumulated H2O2 concentration of 1.43 mol L-1 was reached after 10 hours of continuous electrolysis, showing the potential for practical H2O2 electrosynthesis.

Metal Ion-/Proton-Coupled Electron Transfer (MPCET) on ortho-Quinone.

Quinol/quinone equilibria are ubiquitous in nature and find multiple technological applications, most recently in electrical charge storage. Much research has been devoted to proton-coupled electron transfer (PCET) in such systems and to bidentate complexation of ortho-quinol (catechol) ligands with multivalent metal ions but rarely to the interplay of these two reactions. Here, we investigate the impact of a redox-inactive metal ion, as a complexing and charge-compensating agent, on redox processes of catechol in aqueous solutions, that is, in the presence of proton equilibria. We pay separate attention to their thermodynamics and kinetics, which can be regulated by the pH and buffer capacity. As the proton buffer concentration decreases, proton equilibria during catechol PCET are slower to establish, thus kinetically prioritizing the participation of the metal ion rather than the proton in the redox charge compensation. Making use of this kinetic interplay can be a general strategy to conceive organic battery cathodes for proton-free metal-ion aqueous batteries.

Multiplexed Fluoro-electrochemical Single-Molecule Counting Enabled by SiC Semiconducting Nanofilm.

A major challenge for ultrasensitive analysis is the high-efficiency determination of different target single molecules in parallel with high accuracy. Herein, we developed a quantitative fluoro-electrochemical imaging approach for direct multiplexed single-molecule counting with a SiC-nanofilm-modified indium tin oxide transparent electrode. The nanofilm could control local pH through proton-coupled electron transfer in a lower potential range and further induce direct electrochemical oxidation of the dye molecules with a higher applied potential. The fluoro-electrochemical responses of immobilized single molecules with different pH values and redox behaviors could thus be distinguished within the same fluorescence channels. This method yields nonamplified direct counting of single molecules, as indicated by excellent linear responses in the picomolar range. The successful distinction of seven different randomly mixed dyes underscores the versatility and efficacy of the proposed method in the highly accurate determination of single dye molecules, paving the way for highly parallel single-molecule detection for diverse applications.

Dual behavior of histidine during sensitized photo-oxidation of model compounds and proteins

Histidine (His) photo-oxidation has been widely investigated with several transient and stable products characterized, especially for aerobic conditions. Due to its role and structure, His-side chain can be a key player in the quenching of excited states such as the triplet state of the photosensitizer 3-carboxybenzophenone (3CB*). The capacity of His and its derivatives to quench 3CB* under anaerobic conditions are characterized in the current study by laser flash photolysis, with the resulting oxidation products examined by mass spectrometry to determine the reaction mechanism. The latter include adducts of the 3-carboxybenzophenone ketyl radical (CBH•) to the imidazole ring (Imid-CH2-CBH), His-His dimers, and other products with lower yields. The data obtained with model compounds are compared to those obtained with more complicated systems, including the peptide Exendin-4, and the protein MtHpt1. The data obtained from transient spectroscopy and product analyses indicate that two CB* quenching mechanisms occur: (i) proton-coupled electron transfer (as reported previously) yielding radicals that can recombine to give His-His dimers and CBH-adducts, and (ii) energy transfer yielding 3His* undergoing further reaction leading to formation of Imidazyl-CH2-CBH adduct. The latter, unexpected process only occurs when His and its derivatives have a free α-amino group. This process yielded a novel adduct between the imidazole ring and the CBH• formed by sensitizer reduction.

Reversed I1Cu4 single-atom sites for superior neutral ammonia electrosynthesis with nitrate

Electrochemical ammonia (NH3) synthesis from nitrate reduction (NITRR) offers an appealing solution for addressing environmental concerns and the energy crisis. However, most of the developed electrocatalysts reduce NO3- to NH3 via a hydrogen (H*)-mediated reduction mechanism, which suffers from undesired H*-H* dimerization to H2, resulting in unsatisfactory NH3 yields. Herein, we demonstrate that reversed I1Cu4 single-atom sites, prepared by anchoring iodine single atoms on the Cu surface, realized superior NITRR with a superior ammonia yield rate of 4.36 mg h-1 cm-2 and a Faradaic efficiency of 98.5% under neutral conditions via a proton-coupled electron transfer (PCET) mechanism, far beyond those of traditional Cu sites (NH3 yield rate of 0.082 mg h-1 cm-2 and Faradaic efficiency of 36.5%) and most of H*-mediated NITRR electrocatalysts. Theoretical calculations revealed that I single atoms can regulate the local electronic structures of adjacent Cu sites in favor of stronger O-end-bidentate NO3- adsorption with dual electron transfer channels and suppress the H* formation from the H2O dissociation, thus switching the NITRR mechanism from H*-mediated reduction to PCET. By integrating the monolithic I1Cu4 single-atom electrode into a flow-through device for continuous NITRR and in situ ammonia recovery, an industrial-level current density of 1 A cm-2 was achieved along with a NH3 yield rate of 69.4 mg h-1 cm-2. This study offers reversed single-atom sites for electrochemical ammonia synthesis with nitrate wastewater and sheds light on the importance of switching catalytic mechanisms in improving the performance of electrochemical reactions.

Conformational control over proton-coupled electron transfer in metalloenzymes.

From the reduction of dinitrogen to the oxidation of water, thechemical transformations catalysed by metalloenzymes underlie global geochemical and biochemical cycles. These reactions represent some of the most kinetically and thermodynamically challenging processes knownand require the complex choreography of the fundamental building blocks of nature, electrons and protons, to be carried out with utmost precision and accuracy. The rate-determining step of catalysis in many metalloenzymes consists of aprotein structural rearrangement, suggestingthat nature has evolved to leverage macroscopic changes in protein molecularstructure to control subatomicchanges in metallocofactor electronicstructure. The proton-coupled electron transfermechanisms operative in nitrogenase, photosystem II and ribonucleotide reductase exemplify this interplay between molecular and electronic structural control. We present the culmination of decades of study on each of these systems and clarify what is known regarding the interplay between structural changesand functional outcomes in these metalloenzyme linchpins.

Promoting Oxygen Evolution Electrocatalysis by Coordination Engineering in Cobalt Phosphate.

Understanding the structure-activity correlation is an important prerequisite for the rational design of high-efficiency electrocatalysts at the atomic level. However, the effect of coordination environment on electrocatalytic oxygen evolution reaction (OER) remains enigmatic. In this work, the regulation of proton transfer involved in water oxidation by coordination engineering based on Co3(PO4)2 and CoHPO4 is reported. The HPO4 2- anion has intermediate pKa value between Co(II)-H2O and Co(III)-H2O to be served as an appealing proton-coupled electron transfer (PCET) induction group. From theoretical calculations, the pH-dependent OER properties, deuterium kinetic isotope effects, operando electrochemical impedance spectroscopy (EIS) and Raman studies, the CoHPO4 catalyst beneficially reduces the energy barrier of proton hopping and modulates the formation energy of high-valent Co species, thereby enhancing OER activity. This work demonstrates a promising strategy that involves tuning the local coordination environment to optimize PCET steps and electrocatalytic activities for electrochemical applications. In addition, the designed system offers a motif to understand the structure-efficiency relationship from those amino-acid residue with proton buffer ability in natural photosynthesis.

Enhancing proton-coupled electron transfer drives efficient methanogenesis in anaerobic digestion

The enhancement of electron or proton transfer between syntrophic microbes has been widely recognised as a means for improving methane generation. However, the uncoupled supplementation of electrons and protons in multiphase anaerobic environment hinders the balanced uptake of electrons and protons in the cytoplasm of methanogens, limiting methanogenesis efficiency. Herein, the cooperative effect of a proton-conductive material (PM) and an electron-conductive material (EM) in enhancing proton-coupled electron transfer (PCET) and driving efficient methanogenesis in anaerobic digestion was investigated. The cooperation of the PM and EM significantly increased methane production and the maximum methane generation rate by 78.9 % and 103.5 %, respectively, indicating enhanced methanogenesis efficiency. Analysis of the physicochemical properties, biochemical components, and microbial dynamics revealed that the cooperation of the PM and EM improved the metabolism of syntrophic microbes, which was critically dependent on electron and proton transfer. This enhancement was primarily due to the improvement in PCET, as mainly supported by hydrogen/deuterium kinetic isotope effect measurements, multi-omics integration analyses and reaction thermodynamics and kinetics analyses. Our findings suggest that the PCET enhancement stimulated efficient membrane-bound enzymatic reactions related to electron-driven proton translocation and facilitated electron and proton supply for CO2 reduction to realise highly efficient methane generation. These findings are expected to provide a new insight into effective electron and proton coupling transfer for methanogenic metabolism in multiphase anaerobic environments.

Enhancing the production of reactive oxygen species in the rhizosphere to promote contaminants degradation in sediments by electrically strengthening microbial extracellular electron transfer

The production of reactive oxygen species (ROS) in the rhizosphere is limited by the low extracellular electron transfer capacity of indigenous microorganisms. In the present study, electrical stimulation was used to promote the generation of rhizospheric ROS by accelerating extracellular electron transfer. The result showed that •OH concentrations in the electrically stimulated group (ES group) exceeded the control group by 15.76 %. Accordingly, the removal rate of the target pollutant (i.e., 2,4-dichlorophenol, and sulfamethoxazole) was 20.01 %−24.80 % higher in the ES group than in the control group. The sediment of the ES group had a higher capacity (30.55 %) and a lower electrical resistance (29.15 %) compared to the control group, which subsequently promoted the dissimilatory iron reduction to produce Fe(II) for triggering a Fenton-like process. The increased extracellular respiratory capacity under electrical stimulation could be attributed to the polarization of C-N and CO bonds, which provided more electron storage sites and thus participated in proton-coupled electron transfer. In addition, the concentration of ATP and co-enzymes (NADH/NAD+ and Complex I/Complex III), reflecting electron exchange within respiratory chains, increased distinctly under electrical stimulation. Applying electrical stimulation seemed feasible to increase ROS production and contaminant degradation in the rhizosphere, deepening the understanding of electrical stimulation to promote the production of ROS in the natural system.

A synergetic cocatalyst for conversion of carbon dioxide, sunlight, and water into methanol

The conversion of CO2 into liquid fuels, using only sunlight and water, offers a promising path to carbon neutrality. An outstanding challenge is to achieve high efficiency and product selectivity. Here, we introduce a wireless photocatalytic architecture for conversion of CO2 and water into methanol and oxygen. The catalytic material consists of semiconducting nanowires decorated with core-shell nanoparticles, with a copper-rhodium core and a chromium oxide shell. The Rh/CrOOH interface provides a unidirectional channel for proton reduction, enabling hydrogen spillover at the core-shell interface. The vectorial transfer of protons, electrons, and hydrogen atoms allows for switching the mechanism of CO2 reduction from a proton-coupled electron transfer pathway in aqueous solution to hydrogenation of CO2 with a solar-to-methanol efficiency of 0.22%. The reported findings demonstrate a highly efficient, stable, and scalable wireless system for synthesis of methanol from CO2 that could provide a viable path toward carbon neutrality and environmental sustainability.

Buffering Donor Shuttles in Proton-Coupled Electron Transfer Kinetics for Electrochemical Hydrogenation of Hydroxyacetone to Propylene Glycol.

Electrochemical hydrogenation reactions demand rapid proton-coupled electron transfer at the electrode surface, the kinetics of which depend closely on pH. Buffer electrolytes are extensively employed to regulate pH over a wide range. However, the specific role of buffer species should be taken into account when interpreting the intrinsic pH dependence, which is easily overlooked in the current research. Herein, we report the electrochemical hydrogenation of hydroxyacetone, derived from glycerol feedstock, to propylene glycol with a faradaic efficiency of 56 ± 5% on a polycrystalline Cu electrode. The reaction activities are comparable in citrate, phosphate, and borate buffer electrolytes, encompassing different buffer identities and pH. The electrokinetic profile reveals that citrate is a site-blocking adsorbate on the Cu surface, thereby decreasing buffer concentration and increasing pH will enhance the reaction rate; phosphate is an explicit proton donor, which promotes the interfacial rate by increasing buffer concentration and decreasing pH, while borate is an innocent buffer, which can be used to investigate the intrinsic pH effect. Combined with in situ SEIRAS, we demonstrate that water is the primary proton source in citrate and borate electrolytes, reiterating the rationality of the proposed mechanism based on the microkinetic modeling. Our results emphasize the intrinsic complexity of the buffer system on the kinetic activity for electrocatalysis. It calls for special care when we diagnose the mechanistic pathway in buffer electrolytes convoluted by different buffer identities and pH.

Wavelength-Selective Xanthene-Based Monochromophoric Photoremovable Protecting Groups for Tuning Soft Matter Material Properties.

Photocontrolled deprotection of specific functional groups has garnered significant interest over the past two decades. Notably, the selective deprotection of distinct groups based on wavelength has emerged as a prominent focus in recent research. The achievement of this objective has primarily involved the utilization of linker-based bichromophoric systems and diverse cocktail mixtures of photoresponsive protecting groups (PRPGs), each responsive to varying wavelengths of light. Herein, we present the first wavelength-selective monochromophoric system based on a hydroxanthene moiety, enabling the wavelength-selective release of two distinct functionalities under 450 and 600 nm light, respectively. The mechanism of the wavelength-selective photodegradation was thoroughly investigated by 1H NMR, UV-vis, and fluorescence spectroscopy, suggesting a proton-coupled electron transfer mechanism in the first photorelease step and electron transfer based arylmethyl type of photorelease in the second step. The utility of the xanthene-based wavelength-selective PRPGs was demonstrated in the multistep degradation of microparticles and dual-color tuning of polymer chain architecture, thus opening an avenue to design advanced photoreactive wavelength-controlled systems for applications in soft matter materials.