A comprehensive understanding of the intricate water/gas two-phase flow in sedimentary pores is essential for accurately predicting gas production following the in-situ dissociation of natural gas hydrates, as it is crucial for optimizing resource extraction strategies. This study constructed three typical clay slit nanopore models with distinct wettability characteristics – hydrophilic, relatively hydrophobic, and Janus hybrid-wettability – and used molecular dynamics simulations to investigate the spatial distribution and transport dynamics of two-phase fluids under varying water saturation conditions. The results revealed a significant negative correlation between water saturation and gas relative permeability. When water saturation reaches a critical threshold, the water lock effect occurs, blocking gas flow. Pore wettability plays a key regulatory role in water/gas phase dynamics via influencing the formation pathways of water locks. In relatively hydrophobic pores, weaker solid-water interactions promote the rapid clustering of water molecules, forming water locks, while hydrophilic surfaces enable water lock formation through gradual thickening of the liquid film. In Janus pores with low water saturation, strong electrostatic interactions between oppositely charged pore walls facilitate the formation of discrete water bridge networks, maintaining “gas windows” that allow gas flow, although these windows eventually close as saturation increases. The lower the water saturation, the more favorable it is for gas transport; in contrast, hydrophilic pores exhibit higher gas transport efficiency. Our findings provide valuable molecular-scale insights into how wettability governs multiphase flow transport, offering a theoretical foundation for reservoir modification and seepage control in natural gas hydrate recovery.

Emerging as a new class of two-dimensional materials with atomically thin layers, MBenes have great potential for many important applications such as energy storage and electrocatalysis. Toward mitigating carbon footprint, there has been increasing interest in CO₂/CO conversion on MBenes, but mostly focused on C₁ products. C₂₊ chemicals generally possess higher energy densities and wider applications than C₁ counterparts. However, C–C coupling is technically challenging because of high energy requirement and currently few catalysts are suited for this process. Here, we explore electrochemical CO reduction reaction to C₂ chemicals on Mo₂B₂O₂ MBene via density-functional theory calculations. Remarkably, the most favorable CO–COH coupling is revealed to be a spontaneous and barrierless process, making Mo₂B₂O₂ an efficient catalyst for C–C coupling. Among C₁ and C₂ chemicals, ethanol is predicted to be the primary product. Furthermore, by charge and bond analysis, it is unraveled that there exist significantly more unbonded electrons in the C atom of intermediate *COH than other C₁ intermediates, which is responsible for the facile C–C coupling. From an atomic scale, this work provides microscopic insight into C–C coupling process and suggests Mo₂B₂O₂ a promising catalyst for electrochemical CO reduction to C₂ chemicals.