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Abstract China has large, estimated potential for direct air carbon capture and storage (DACCS) but its deployment locations and impacts at the subnational scale remain unclear. This is largely because higher spatial resolution studies on carbon dioxide removal (CDR) in China have focused mainly on bioenergy with carbon capture and storage. This study uses a spatially detailed integrated energy-economy-climate model to evaluate DACCS for 31 provinces in China as the country pursues its goal of climate neutrality by 2060. We find that DACCS could expand China’s negative emissions capacity, particularly under sustainability-minded limits on bioenergy supply that are informed by bottom-up studies. But providing low-carbon electricity for multiple GtCO₂yr⁻¹DACCS may require over 600 GW of additional wind and solar capacity nationwide and comprise up to 30% of electricity demand in China’s northern provinces. Investment requirements for DACCS range from $330 to $530 billion by 2060 but could be repaid manyfold in the form of avoided mitigation costs, which DACCS deployment could reduce by up to $6 trillion over the same period. Enhanced efforts to lower residual CO₂emissions that must be offset with CDR under a net-zero paradigm reduce but do not eliminate the use of DACCS for mitigation. For decision-makers and the energy-economy models guiding them, our results highlight the value of expanding beyond the current reliance on biomass for negative emissions in China. 

Abstract In this work, we employed flame spray pyrolysis (FSP), a high‐temperature synthesis method, to control the formation of Pd structures on the CeO₂support. Multiple types of Pd structures deposited on CeO₂are observed on FSP‐made samples. Our results show that the oxidizing environment during FSP synthesis facilitates the formation of incorporated Pd²⁺structures, along with highly dispersed Pd²⁺, Pd⁰nanoparticles, and Pd° clusters formed under the reducing synthesis condition. Notably, these Pd²⁺species remained stable at temperatures up to 400 °C. The catalysts containing both highly dispersed Pd²⁺nanoparticles and incorporated Pd²⁺species demonstrated superior methane oxidation activity, with higher turnover frequencies than those containing only one type of Pd²⁺structure. However, hydrothermal pretreatment in the presence of water vapor led to partial deactivation, likely due to structural alterations in the Pd species or the interaction with the CeO₂support, which reduced the stability and effectiveness of the active sites. This study underscores the importance of both highly dispersed and incorporated Pd²⁺species in enhancing catalytic performance and highlights the challenges posed by water‐induced deactivation in practical applications. 

The implementation of synthetic polymer membranes in gas separations, ranging from natural gas sweetening, hydrogen separation, helium recovery, carbon capture, oxygen/nitrogen enrichment, etc. , has stimulated the vigorous development of high-performance membrane materials. However, size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity, primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size distribution. Herein, we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance, with an emphasis on membranes with hourglass-shaped or bimodally distributed microcavities. State-of-the-art strategies to construct tailorable and hierarchically microporous structures, microporosity characterization, and microcavity architecture that govern gas separation performance are systematically summarized.