Amorphous ZnSnO x Hollow Spheres Enable Highly Efficient CO 2 Reduction.

Carbon dioxide (CO 2 ) adsorption and electron transport play an important role in CO 2 reduction reaction (CO 2 RR). Herein, we have demonstrated a new class of diverse hollow ZnSnO x (ZSO) through the amorphization of hydroxides to enhance CO 2 adsorption and accelerate electron transport. The amorphization is occurred by calcination process, as indicated by Fourier transform infrared spectroscopy and Raman spectra. In particular, the ZnSnO x hollow spheres (ZSO HSs) achieve a high Faradaic efficiency (FE) of HCOOH up to 92.7 % at best, outperforming the commercial ZSO (Comm. ZSO, 85.7 %). ZSO HSs also exhibit durable stability with negligible activity decay after 10 h of successive electrolysis. In-situ attenuated total reflectance infrared absorption spectroscopy further reveals strong adsorption of CO 2 and rapid intermediate configuration transformation in amorphous ZSO HSs. This work demonstrates the practical application of ZSO for CO 2 RR and provides a new insight to create efficient CO 2 RR electrocatalysts.