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The evergrowing plastic production and the caused concerns of plastic waste accumulation have stimulated the need for waste plastic chemical recycling/valorization. Current methods suffer from harsh reaction conditions and long reaction time. Herein we demonstrate a non-thermal plasma-assisted method for rapid hydrogenolysis of polystyrene (PS) at ambient temperature and atmospheric pressure, generating high yield (>40 wt%) of C₁–C₃hydrocarbons and ethylene being the dominant gas product (Selectivity of ethylene,S_C2H4 > 70%) within ~10 min. The fast reaction kinetics is attributed to highly active hydrogen plasma, which can effectively break bonds in polymer and initiate hydrogenolysis under mild condition. Efficient hydrogenolysis of post-consumer PS materials using this method is also demonstrated, suggesting a promising approach for fast retrieval of small molecular hydrocarbon modules from plastic materials as well as a good capability to process waste plastics in complicated conditions.

 

Formaldehyde is an essential building block for hundreds of chemicals and a promising liquid organic hydrogen carrier (LOHC), yet its indirect energy-intensive synthesis process prohibits it from playing a more significant role. Here we report a direct CO reduction to formaldehyde (CORTF) process that utilizes hydrogen underpotential deposition to overcome the thermodynamic barrier and the scaling relationship restriction. This is the first time that this reaction has been realized under ambient conditions. Using molybdenum phosphide as a catalyst, formaldehyde was produced with nearly a 100% faradaic efficiency in aqueous KOH solution, with its formation rate being one order of magnitude higher compared with the state-of-the-art thermal catalysis approach. Simultaneous tuning of the current density and reaction temperature led to a more selective and productive formaldehyde synthesis, indicating the electrochemical and thermal duality of this reaction. DFT calculations revealed that the desorption of the *H 2 CO intermediate likely served as the rate-limiting step, and the participation of H 2 O made the reaction thermodynamically favorable. Furthermore, a full-cell reaction set-up was demonstrated with CO hydrogenation to HCHO achieved without any energy input, which fully realized the spontaneous potential of the reaction. Our study shows the feasibility of combining thermal and electrochemical approaches for realizing the thermodynamics and for scaling relationship-confined reactions, which could serve as a new strategy in future reaction design. 

Polymer solar cells (PSCs) with a bulk heterojunction (BHJ) device structure have incredible advantages, such as low‐cost fabrication and flexibility. However, the power conversion efficiency (PCE) of BHJ PSCs needs to be further improved to realize their practical applications. In this study, boosted PCEs from PSCs based on BHJ composites incorporated with Fe₃O₄magnetic nanoparticles (MNPs), aligned by an external magnetic field (EMF), are reported. It is found that the coercive electric field within the Fe₃O₄MNPs generated by the EMF has a strong and positive influence on the charge generation, which results in a more than 10% increase in free charge carriers. Moreover, the coercive electric field speeds up the charge carrier transport and suppresses charge carrier recombination within PSCs. In addition, a shortened extraction time makes charge carriers more likely to make it to the electrodes. As a result, more than 15% enhancement in PCE is observed from the PSCs based on the BHJ composite incorporated with the Fe₃O₄MNPs and the EMF as compared with that based on the BHJ composite thin film. This work indicates that the incorporation of MNPs and the EMF is a facile way to enhance the PCEs of PSCs.

 

One of the challenges in polymer electrolyte membrane fuel cells (PEMFCs) is developing cost‐effective, active and stable catalyst for oxygen reduction reaction (ORR). Platinum alloy‐based catalyst materials have drawn great attention and been intensively investigated for the excellent activity property, with some of them already exceeding 2020 DOE target for the ORR activity. In the meantime, the electrochemical stability of these Pt alloys remains a challenge to be overcome. This review first highlights important understandings of ORR pathways and mechanisms and then proceeds to summarize recent research progresses on development of Pt alloy catalyst materials. Current obstacles in Pt alloy catalyst research are discussed, with the stability issue being specifically emphasized and a theoretical model being developed for depicting the stability property. This review also provides perspectives of future research directions in this field.

 

In the past years, hybrid perovskite materials have attracted great attention due to their superior optoelectronic properties. In this study, the authors report the utilization of cobalt (Co²⁺) to partially substitute lead (Pb²⁺) for developing novel hybrid perovskite materials, CH₃NH₃Pb_1‐xCo_xI₃(wherexis nominal ratio,x= 0, 0.1, 0.2 and 0.4). It is found that the novel perovskite thin films possess a cubic crystal structure with superior thin film morphology and larger grain size, which is significantly different from pristine thin film, which possesses the tetragonal crystal structure, with smaller grain size. Moreover, it is found that the 3d orbital of Co²⁺ensures higher electron mobilities and electrical conductivities of the CH₃NH₃Pb_1‐xCo_xI₃thin films than those of pristine CH₃NH₃Pb₄thin film. As a result, a power conversion efficiency of 21.43% is observed from perovskite solar cells fabricated by the CH₃NH₃Pb_0.9Co_0.1I₃thin film. Thus, the utilization of Co, partially substituting for Pb to tune physical properties of hybrid perovskite materials provides a facile way to boost device performance of perovskite solar cells.