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Abstract Efficient electrosynthesis of methanol from CO2 is hindered by the competitive adsorption of CO2 over CO on cobalt phthalocyanine-based catalysts, which prevents the CO intermediate from further reducing to CH3OH. In this work, we show that tuning the electrode architecture, specifically by extending the electrode area and increasing the catalyst layer thickness in the inlet region, can overcome this challenge by controlling the spatial distribution of CO. A 5-fold extension of the electrode area (from 1 to 5 cm2) and subsequently the serpentine flow channel allows CO2 to be progressively converted to CO along the electrode, enriching CO in the downstream region and facilitating its further conversion to methanol. Likewise, a thicker catalyst layer upstream boosts CO generation upstream, which then drives higher CH3OH formation in downstream regions. This approach yields over 10 times enhancement in methanol current density (>30 mA/cm2) and increases methanol Faradaic efficiency by over 30%, without altering the catalyst molecules or operating potential. Multiphysics modeling confirms that the extended channel increases local CO partial pressure and residence time within the catalyst layer, directly correlating with the observed rise in methanol output. Beyond simply increasing gas residence time, the segment-resolved electrode reveals how CO generation and CO utilization evolve spatially along the enlarged GDE. The S1-thickened architecture further demonstrates that methanol formation can be enhanced by redistributing CO-generation capacity along a fixed channel length, highlighting spatial intermediate management as a scale-up-oriented electrode design principle. Our results highlight a strategy for CO2-to-methanol conversion by spatially managing CO abundance via electrode design, which can be a powerful complement to catalyst material innovations. 

In the laser powder bed fusion additive manufacturing process, the quality of fabrications is intricately tied to the laser–matter interaction, specifically the formation of the melt pool. This study experimentally examined the intricacies of melt pool characteristics and surface topography across diverse laser powers and speeds via single-track laser scanning on a bare plate and powder bed for 316L stainless steel. The results reveal that the presence of a powder layer amplifies melt pool instability and worsens irregularities due to increased laser absorption and the introduction of uneven mass from the powder. To provide a comprehensive understanding of melt pool dynamics, a high-fidelity computational model encompassing fluid dynamics, heat transfer, vaporization, and solidification was developed. It was validated against the measured melt pool dimensions and morphology, effectively predicting conduction and keyholing modes with irregular surface features. Particularly, the model explained the forming mechanisms of a defective morphology, termed swell-undercut, at high power and speed conditions, detailing the roles of recoil pressure and liquid refilling. As an application, multiple-track simulations replicate the surface features on cubic samples under two distinct process conditions, showcasing the potential of the laser–matter interaction model for process optimization.