Nature-Inspired Multifunctional Nano-Microreactors: Pd Nanoclusters-Integrated Bioengineered Skin Channels for...

Nature-inspired design principles offer powerful strategies for engineering advanced catalytic materials with multifunctional microenvironment proximal to active sites. Here, bioengineered multifunctional skin nano-microchannels (N─MCs) integrated with Pd nanoclusters (Pd/N─MCs) are presented for the first time for remarkably preventing challenges of product inhibition and hydrogen adherence during its generation from ammonia borane (AB). Pd/N─MCs, with its peculiar mechanism of action, differentiate it from all the reported catalytic systems till date, which are known to be affected/deactivated by product inhibition and hydrogen adherence. The N─MCs feature a unique hydrophilic-aerophobic environment and tunable surface chemistry, effectively mitigating product inhibition and hydrogen bubble adherence during its performance. The lysyl-rich matrix of hierarchically-assembled collagen facilitates AB uptake and activation at Pd sites, while promoting borate desorption to sustain high catalytic turnover. The aqueous microchannels, with a hydrogen bubble contact angle of ≈153°, destabilize generated hydrogen gas bubbles and facilitate their release. Additionally, exhaustive methylation of lysyl amino groups results in positively charged [Pd/N─MCs]⁺, enhancing microenvironment polarity and achieving a high turnover frequency (TOF) of 3589 h^-1. This nature-inspired platform bridges biological precision with materials science, providing a scalable and sustainable strategy for multifunctional nano-microreactors and advancing nature-inspired systems for efficient hydrogen production.